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A PRACTICAL GUIDE TO THE DESIGN, CONSTRUCTION, AND 
REPAIR OF AUTOMOBILE MECHANISMS 


BY 

MORRIS A. HALL 

Kditor, Automotive Enyineeriny; Formerly Managing I'Mitor, Motor Life, Editor, The Commercial Vehicle, 
etc.; Authorof “What Every Automobile Owner Should Know.” Member, Society of Auto¬ 
mobile Engineers; Member, American Society of Mechanical Engineers 


ILLUSTRATED 



AMERICAN TECHNICAL SOCIETY 
CHICAGO 
1919 





COPYRIGHT, 1919 , HY 
AMERICAN TECHNICAL SOCIETY 


COPYRIGHTED IN GREAT BRITAIN 
ALL RIGHTS RESERVED 





©CU536^76 


0 


-' \ 


1 



INTRODUCTION 


T HE modern automobile is mechanically a line piece of 
engineering and it represents in its development the 
product of the best technical brains of the country. The 
engine has changed from the halting, wheezy, unreliable con¬ 
traption of fifteen years ago into a perfectly dependable, well- 
behaved, and sweet-running mechanism which carries its owner 
at high or low speed, in the heat of summer or the cold of 
winter, over all sorts of road with exceedingly rare periods 
of distress or failure. The same evolution has taken place 
with each part of the automobile until practically all the 
changes in present-day models are simply refinements of the 
existing mechanisms. No expenditure of money or skill has 
been spared to make the automobile as near perfect as pos¬ 
sible. As a result, it stands today one of our best examples of 
well-rounded development, a device which has had more to 
do with our progress in production manufacturing in the last 
ten years than any other single machine which could be men¬ 
tioned. Therefore, it behooves those who are interested in 
this development to study the construction and design factors 
with great attention. Lessons are to be learned from the 
evolution of this device, from the failure of that design, and 
the study of “near perfection” is always profitable. 

(J This volume has been designed not only for the man who 
is interested in things mechanical, but more especially for 
the designer, for the mechanic who is engaged in automobile 
construction and repair work, and for owners and chauffeurs 
who wish to be their own repairmen. The discussion of the 
construction of valves, clutch, transmission, etc., is confined 
mainly to the standard types without much attempt to trace 
the historic background. As to the repair sections, there are 
many ways of effecting repairs on an automobile, but the 
advice here given is based on careful observation and broad 
experience. The suggestions range from the engine to the 
differential, from the steering gear to the tires. The excep¬ 
tionally full section on carburetors and carburetor adjustments 
and the section on tire vulcanizing, with the description of 
proper tire repair methods, will be found especially helpful. 
No attempt has been made to cover “Ignition, Starting, and 
Lighting Systems,” as this has received an exhaustive treat¬ 
ment under that title issued by the same publishers. 















*r.~ 




















CONTENTS 

Page 

Engine group . 11 

General engine features. 15 

Cylinder forms and construction. 22 

Pistons and accessories. 48 

Connecting rods . G1 

Crankshafts . 72 

Crankcases . S4 

Carburetors and carburetion. 99 

Function of carburetor. 99 

Effect of heavier fuels. 99 

Classification. 1U1 

Throttle valves . 103 

Carburetor operation . 112 

Kerosene and heavy fuel carburetors. 180 

Carburetor troubles and remedies. 194 

Inlet manifold design and construction. 205 

Changes in design. 205 

Heating the charge. 209 

Inlet manifold troubles. 210 

Fuel supply . 211 

Tank placing . 211 

Fuel feeding . 211 

Piping and connections. 210 

Reserve tank . 217 

Fuel system troubles and repairs. 218 

Valves and their mechanism. 227 

Valve features . 227 

Poppet-valve gears . 232 

Repairing valve parts. 252 































CONTENTS 


Page 

Valves and their mechanism (continued) 


Sliding sleeve valves. 271 

Rotating valves . 278 

Exhaust system . 279 

Cooling systems . 286 

Water cooling . 286 

Air cooling . 300 

Troubles and adjustments. 302 


Lubrication system. 305 

Motor lubrication . 305 

General lubrication . 321 

Oils and greases. 322 

Lubrication troubles and remedies. 325 

Hearings . 330 


Flywheel sub-group . 337 

Characteristics of flywheel. 337 

Methods of fastening flywheel. 339 

Flywheel markings . 339 


Clutches . 

Cone type . 

Contracting-band type . 

Expanding-band type . 

Disc type . 

Magnetic type . 

(dutch operation . 

Clutch troubles and remedies 


351 

352 

354 

355 

356 
364 
366 
370 


Transmissions . 380 

Sliding gears. 381 

Individual clutch . 395 

Planetary gears . 399 

Friction disc . 401 

Troubles and repairs. 409 

Gears . 421 

Types of gear-cutting machines. 421 

Types of gears in automobiles. 428 





































CONTENTS 


Page 

Steering group. 445 

Steering gears . 445 

Steering wheels . 470 

Steering rods .'. 474 

Front-wheel drive . 480 

Four-wheel drive . 482 

Electric drive . 489 

Front axles ... 491 

Chassis group . 508 

Frames . 509 

Springs . 530 - 

Shock absorbers .. 549 

Final-drive group . 569 

Rear axle . 581 

Brakes . 604 

Wheels . 622 

Tires . 645 

Rims . 654 


4 


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SECTION OF BUICK SIX-CYLINDER ENGINE ON 1918 CAR 

Courtesy of Buick Motor Company, Flint, Michigan 











































































































































































GASOLINE AUTOMOBILES 

PART I 


INTRODUCTORY 

Of all the applications of the internal-combustion motor, it is 
safe to say that none is more important than that applied to the 
propulsion of the modern motor vehicle—the automobile—which 
nowadays throngs the roads and streets of nearly every country in 
the world, and serves a myriad of utilities as they never have been 
and never could be served by animal transportation. 

Standardized, inexpensive to buy, and inexpensive to operate, 
almost unfailingly reliable, and proved capable of use in the hands 
of even the most unmechanical of operators, the automobile is at 
last coming fully into its own. Its design has become recognized as a 
branch of engineering by itself, its manufacture constitutes one of 
the greatest of the mechanical industries, and its use is a common 
necessity. 

Naturally, in so tremendous a development, there is sustained 
by the general public every possible sort of relationship with the 
automobile, from that of the merely casual observer and occasional 
user, to the more interested owner; and thence on, in ever closer 
touch with the full significances of this field of engineering, to the 
high-skilled and well-paid drivers of cars, the experts who repair 
them, the shopmen who build them, and the engineers and draftsmen 
who design them. 

All along this line there is an increasing need for knowledge—a 
demand for definite, specific, usable information concerning the 
science upon which the motor vehicle is based, and the practice upon 
which its construction and performance are founded. 

In no other important field of engineering is there such a lack of 
correct and authoritative literature as in the automobile field. 

This undoubtedly is due to two conditions that have been 
involved in the rapid growth of the automobile from a mere experi¬ 
ment to an achieved and commercial fact. The first condition is 





2 


GASOLINE AUTOMOBILES 


the circumstance that the men who have deeply studied the auto¬ 
mobile from an engineering standpoint, and who are best informed 
about it, have not had the time to place upon paper the facts with 
which they are acquainted. The second condition—resulting from 
the rapid development of automobile design and engineering practice 
has left no time for the establishment of a formulated science, upon 
which textbooks of a genuine and permanent authority may be based. 

What follows will be an advanced and comprehensive treatment 
of the very latest devices applied in automobile engineering. All 
are carefully described, their essentials fully analyzed, and their 
important details fully illustrated. 

Historical material of any kind is useless in a work of this sort, 
which is intended primarily for the man in the shop, who does the 
actual work of completing the car in the first place, and the man in 
the garage who keeps it in running order thereafter. It will suffice to 
say that while most of the worthy efforts and early progress in the 
development of the explosion motor and the automobile were made 
abroad, American designers and American workmen have since 
shown the way in this field to the whole world, so that today we import 
a negligible number of motors and cars, while we export to every other 
country of the world. 

GENERAL OUTLINE OF MOTOR=CAR CONSTRUCTION 

In general, all motor cars follow along the same broad lines. So 
much has this become the case in the last few years that a large 
number of the parts, units, and accessories entering into the con¬ 
struction of the car have become standardized and may, to a certain 
extent, be taken off one car and placed on another without exten¬ 
sive alteration. This has been done, too, without interfering in any 
way with the initiative of the various designers. 

Groups and Parts. Practically all modern gasoline motor cars 
may be divided, in a mechanical sense, into six groups of parts or 
units. These are: (1) the engine, or power-producing group; 
(2) the clutch group, needed, as will be explained later on, with all 
forms of explosion motor; (3) the transmission, or gearset, for pro¬ 
ducing the various car speeds and different powers, while the engine 
gives a practically constant speed and power output; (4) the final 
drive group, which connects the speed variator or transmission with 


GASOLINE AUTOMOBILES 


3 


the rear wheels, and thus propels the car. Of necessity, this includes 
the rear axle, while the front axle is usually grouped with the rear; 

(5) the steering device, for controlling the direction of motion; and 

(6) the frame, upon which all these and their various accessories 

are hung, with the springs for suspending the frame upon the axles 
of the car. There is, of course, a seventh group, the body, but that 
need not be discussed here, since reference is now made only to the 
mechanical parts. h 

Engine Group. In the large diagram of a modern motor car, 
Fig. 1, the sectional side view is shown above, and the plan view 
below. In this, note that the engine is placed at the front of the 
outfit. This is now the position nearly all modern motor car manu¬ 
facturers use. A few cars have the motor located on the rear axle 
to save the parts necessary for connecting the two, while formerly 
the middle position was a favorite one. The purpose of the engine 
is to generate the power. This is done by the drawing-in, compressing, 
and exploding of gas produced from gasoline. 

Cylinder and Crankshaft Sub-Group. All this work is actually done 
within the cylinder, which really forms the basic working medium of 
the engine. The actual drawing-in of the gas, its compression and 
explosion are accomplished by the movements of the piston up and 
down in the cylinder bore. The piston is moved upward and down¬ 
ward by the rotation of the crankshaft except when the explosion 
reverses the situation, and the piston moves the crankshaft, to which 
it is attached by means of the connecting rod. The piston is made to 
fit tightly in the cylinder by means of piston rings, which are com¬ 
pressed into slots formed in the outside of the piston for this purpose. 
The connecting rod is forced to rotate by its attachment at the lower 
end to one of the crankpins of the crankshaft, which is held in the 
crankshaft bearings fastened in the crankcase. It is enabled to turn 
slightly at the upper, or piston, end by being pivoted on the piston 
pin or wrist pin. For convenience the crankcase is usually made in 
two parts, called the upper and lower halves. Sometimes the cylinder 
is also made with a removable cylinder head, or a smaller removable 
cylinder cover. The majority of modern motors have the valves 
enclosed by removable cylinder valve covers. 

Carburetion Sub-Group. The production of the gas necessitates 
what is called a carburetor , a good-sized fuel tank, and piping to connect 


4 


GASOLINE AUTOMOBILES 


the two. The fuel is not always pure and must be filtered through a 
strainer. A cock must be provided in the piping for turning the flow 



. a 

of gas from the tank to the carburetor on and off, while the gas 
produced in the carburetor is taken into the engine through an Met 































































































































































































































































































GASOLINE AUTOMOBILES 


5 


manifold. These and other parts, the functions and construction 
of which will be explained in full later on, constitute the carburetion 
sub-group. 

Inlet and Exhaust J alves. In order to get the gas, which is 
produced by the carburetion group, into the motor cylinders at the 
proper time and in the proper quantity, inlet valves are necessary. 
These valves are operated by cams on a camshaft. The camshaft, 
which will be explained in detail later, is driven from the crankshaft 
of the engine. After the gas has been admitted into the cylinders, 
compressed, and exploded, it is of no further use and must be removed 
from the cylinders. As this must be done at the proper time, and as 
the proper quantity must be removed, additional valves known as the 
exhaust valves are necessary. These are also operated by cams on a 
camshaft, driven from the crankshaft. 

Exhaust System. The exhaust gases pass from the cylinder 
through a particular pipe, known as the exhaust manifold , and thence 
to the back of the car. As there remains considerable pressure in 
these gases when allowed to escape freely, they make much noise 
and considerable smoke, so that all cars are required by law to carry 
and use a muffler. The exhaust gases pass through this and thence 
out into the atmosphere. This whole group of parts is called the 
exhaust system. 

Ignition System. The explosion comes in an intermediate stage. 
It is produced by means of an electric spark, made within the cylinders 
by means of a spark plug. The electric current, which is the original 
source of this spark, may be produced by a rotary current producer, 
known as a magneto, or it may be taken from a battery. In either case, 
the current must be brought up to a proper strength, and the various 
sparks must be produced at the exact time they are needed. All this 
calls for auxiliary apparatus. Moreover, the current producer, if it 
be a magneto, must be driven from some rotating shaft, and there 
must be a suitable place provided on the engine to attach it in such a 
way as to provide for quick and easy removal. All this, as a complete 
unit, is called the ignition system. A complete treatment of this 
subject will be found under “Electric Equipment for Gasoline Cars”. 

Cooling System. A great amount of heat is created by the fol¬ 
lowing explosion and subsequent expanding and exhausting of the 
gas. Some idea of this may be gained from the two following state- 




6 


GASOLINE AUTOMOBILES 


ments: The explosion temperature often runs up as high as 3000° F., 
and the exhaust temperature frequently is as high as 1500° F. In 
order to take away this heat, which communicates itself to the walls 
and to parts of the engine wherever it comes in contact with them, 
and, by conduction, to other parts with which it does not contact, 
the parts which are exposed to the greatest heat are surrounded by 
hollow passages, called jackets , through which water is forced, or 
allowed to flow. This might be called a collector of the heat, for it 
is then conducted to the radiator, a device for cooling the water. 
It is there cooled off and then used again. In order to circulate 
the water, a removable pump, driven from some rotating shaft, is used. 
All this, with the necessary piping to connect the various parts, is 
called the cooling system. 

On some cars, notably the Franklin, and on motorcycles, there 
is another type of engine with an air-cooled system. This type will be 
taken up later. 

Lubrication System. To make the various parts rotate within 
one another, bearings, or parts specially designed to facilitate easy 
and efficient rotation, must be used. In and on all such bearings 
a form of lubricant is necessary, also between all sliding parts. 
In order to have a copious supply of oil at certain points, various 
forms of lubricators or oil pumps are needed to circulate it; pipes must 
be provided to carry it; a sight feed, or visible indication that the 
system is working, must be placed in sight of the driver (usually on 
the dashboard); an oil tank for carrying the supply must be provided; 
and a location found for the lubricator or pump, as well as means for 
driving, removing, adjusting, and cleaning it. All this comes under 
the head of the lubrication system. This system covers, in addition, 
isolated points requiring lubrication and the different ways used to 
supply them. 

Starting System. In order to start the engine, a starting handle 
is provided on all older cars, with possibly a primer’ working on the 
carburetor, and other parts. On modern cars, this work of starting 
is done by electricity, which requires a starting motor, a battery, a 
switch for connecting the two, wiring, buttons, and other parts. 
All this combined is called the starting system. For a complete 
treatment of Starting and Lighting Systems see the article ar 
“Electrical Equipment.” 


GASOLINE AUTOMOBILES 


7 


Lighting System. Nearly all modern motor cars have an electric 
lighting system. This includes an electric-current generator; a battery 
to retain the electric current until needed; suitable governing devices 
to control the generation and flow of current; lamps to use the current; 
wiring to connect them with the source; switches to turn the current on 
and off; and other parts. 

Flywheel. At one end of the engine shaft is the flywheel. This 
is a large, wide-faced member of metal, comparatively heavy, the 
function of which is to store energy (by means of rotation) as the 
engine produces it and to give it back to the engine at other parts 
of the cycle when energy is needed, and none is being produced. In 
short, it is a storehouse of energy, absorbing the same from the engine 
and giving back the excess when it is needed. In general, this effect 
is greatest when the mass of metal is farthest from the center, con¬ 
sequently flywheels are made of as large a diameter as is possible, 
considering the frame members. Note this in the illustration, Fig. 1. 

Clutch Group. The clutch is generally located inside the rim of 
the flywheel. This is a 'device, by means of which a positive connec¬ 
tion can be made with the engine or a disconnection from it effected 
at the driver’s will. When such disconnection is made with the engine 
running, it will continue to run idly, and the car will come to a stand¬ 
still. Conversely, when the positive connection is made, the motor 
will drive the clutch and such parts beyond it as are connected-up 
at the time. This arrangement is necessary because of a peculiarity 
in the gas or gasoline engine which cannot start with a load, but must 
be started and allowed to get up speed before any load is thrown upon 
it. The function of the clutch, then, is to disconnect the balance of 
the driving system from the engine, so that it may attain the necessary 
speed to carry a load. When this has been done, the proper gear is 
engaged, the clutch is thrown in, and the engine picks up its load. 

Like other groups, this must have a means of connecting and 
disconnecting, a proper place, proper fastenings, means for adjust¬ 
ment and removal, means for lubrication, and easy access to its parts. 
All this, collectively, is called the clutch group. 

Transmission Group. As has just been pointed out, the gasoline 
engine cannot start with a load; it must get up speed first. When the 
load is first applied it must be light. This necessitates certain gearing , 
so that, when starting, the power of the engine may be multiplied 


8 


GASOLINE AUTOMOBILES 


many times before reaching the wheels and applied to the propulsion 
of the car. Furthermore, it has been found convenient to have a 
series of such reductions or multiplications. These correspond to the 
various speeds of the car, for, obviously, if the power is multiplied by 
means of gearing, it is reduced in speed in the same ratio. This whole 
group of gearing is the transmission or gearset, and the various reduc¬ 
tions are the low, intermediate, and high speed in a three-speed gear¬ 
box’, and low, intermediate, second, and high in a four-speed gearbox. 
A gearbox is always spoken of by its number of forward speeds, but 
there is in all of them, in addition to the forward speeds, a reverse 
speed for backing the car. 

In the usual form, these gears are moved or shifted into and out 
of mesh with one another, according to the driver’s needs. For this 
purpose, shifting gears must be provided within the gearbox, that is, 
the arrangement must be such that the proper gears can be moved 
back and forth, with a shifting lever outside for the driver’s use, and 
proper and accurate connections between the two. The gears must 
be mounted on shafts, these in turn on bearings, the bearings must 
be supported in the gear-case, and this must be supported on the frame. 
In addition, there must be suitable provision in the gear-case cover 
for inspection, adjustments, and repairs; all the moving parts must 
be lubricated; all parts must be protected from the dust, dirt, and 
moisture of the road, etc. All this comprises the transmission or 
gearing group, which properly ranks second to the engine group in 
importance. 

Final Drive Group. Driving Shaft. The connection from the 
transmission to the rear axle in pleasure cars is usually by shaft, 
called the driving shaft. On the majority of motor trucks, however, 
it is by means of double side chains, which will not be discussed here. 
This shaft is sometimes inclosed in a hollow torque tube, with suitable 
connection at the front end to a frame cross-member, and at the rear 
to the axle housing. Its construction is generally such that it contains 
a bearing for the driving shaft at both front and rear ends. In addi¬ 
tion, the majority of final drives contain at least one universal 
joint, and many of them contain two. As its name indicates, this 
will work universally, that is at any angle, its particular function 
in the driving shaft of an automobile being to transmit power 
from a horizontal shaft—that of the engine clutch and trans- 


GASOLINE AUTOMOBILES 


G 


mission to an inclined one—the driving shaft—with as little loss 
as is possible. 

Rear Axle and Differential. The driving shaft drives the rear 
axle through some form of gear, either bevel, worm, or other variety, 
and is usually a two-part shaft. The reason for cutting the rear axle 
is that each wheel must be driven separately in rounding a curve, for 
one travels a greater distance than the other. This seemingly com¬ 
plicated act is produced by a simple set of gearing called the differen¬ 
tial, which is located within the driven gear in the rear axle. Each 
half of this is fixed to one part of the axle shaft. All these gears and 
shafts must have bearings, lubrication, means for adjustment, etc. 
On the outer ends of the axle shafts are mounted the rear wheels, 
which carry some form of tires to make riding more easy. The 
brakes are generally in a hollow drum attached to the wheels. All 
this goes to make up the driving system. 

Steering Group. The front wheels perform a different function. 
They are hung on the steering pivots, so that they can be turned to 
the right or the left as desired. In order to have the wheels work 
together, a rod, called the cross-connecting rod, joins them, while the 
motion is imparted to them by means of another rod, called the 
steering link, w T hich joins the steering lever or arm with the right-hand, 
or left-hand steering pivot. The last-named lever projects downward 
for this purpose from the steering-gear case and is moved forward and 
backward by the rotation of the steering wheel in the driver’s hands. 

The transformation of the rotation or turning motion of the hand 
wheel into a longitudinal movement is accomplished within the 
steering-gear case by means of a worm and gear, a worm and partial 
gear, or by a pair of bevel gears. All these parts need more or less 
adjustment, lubrication, fastening means, etc., the complete group 
being designated as the steering group. 

In addition, the steering wheel and post carry the spark and 
throttle levers, w r ith the rods, etc., for connecting them to the igniting 
apparatus (magneto, timer, etc.) and the carburetor, respectively. 
The purpose of the spark lever is to allow the driver to vary the power 
and speed of his engine by an earlier or later spark, according to his 
driving needs. Similarly, the throttle lever is for the purpose of 
opening or closing the throttle in the intake manifold of the carhu- 
retion system and regulates the amount of gas entering the engine, 


10 


GASOLINE AUTOMOBILES 


thereby increasing or decreasing its power output, or speed. Actually, 
these are parts of the ignition and carburetion systems, respectively, 
but they are usually classified with the steering group, because they 
are located on the steering wheel and post. 

Frame Group. Little need be said about the frame. The side 
members are generally supported by the springs at the front and rear 
ends. The springs are connected to the axles and support the car. 
Th e front cross-member usually supports the radiator and sometimes the 
front end of the engine, too. The rear cross-member usually supports 
the gasoline tank when a rear tank is used. The other cross-members 
may support the engine, transmission, shifting levers, and other parts, 
according to their location. In general, the number and character 
of frame cross-members is slowly changing; the modern tendency 
is toward their elimination. By narrowing the frame at the front, 
the engine can be supported directly on the side members. With the 
units grouped, the same is true of the other important units. 

Formerly, practically all motors and transmissions were sup¬ 
ported on a sub-frame, but it has been found that the same results can 
be obtained when this extra weight is eliminated. Fig. 1 shows a 
sub-frame. 

When the shifting levers are placed on the outside, they are 
fastened to the frame, as is the steering gear; all step, fender, and body 
parts, the under-pan, or splash-pan, for protecting the mechanism 
from road dirt; and usually the headlights. The frame is constructed 
with this idea in view, six bolts generally being used. The muffler 
is usually hung from a rear-frame member. When electric lighting 
and starting are used, the battery is very often hung in a cradle, sup¬ 
ported by the frame, while the hood or bonnet is supported equally 
by the side members of the frame (usually covered with wood), and 
by a rod running from radiator to dash. 

In Fig. 1, it will be noted that the engine group (1) and the clutch 
group (2) are together, really forming one unit. Back of this the 
transmission (3) and the rear axle or final drive group (4) form two 
separate additional units. When the transmission is united with the 
motor (forming a unit power plant) or with the rear axle, one unit is 
practically eliminated. The different functions of the components 
are not changed, but the grouping previously pointed out becomes 
less apparent, for units (1), (2), and (3); or (3) and (4) become one. 


GASOLINE AUTOMOBILES 11 

ENGINE-GROUP ELEMENTS 

GENERAL FEATURES 

In the following pages, the general grouping just outlined will be 
followed consistently, so that the student and worker will be able to 
follow through the construction and repair of the entire car in a reason¬ 
able and logical manner. 

The principles of engine design, and the methods and details of 
engine construction are second to none of the other factors that com¬ 
bine to produce the complete modern automobile. 

How automobile engines operate, the reasons underlying the 
various details of different designs, and the relative merits of different 
constructions are all too little understood by most of those who have 
to do in a practical way with the new conveyance. 

Cycles of Engine Operation. In all motors of any type other 
than those in which there is a perfectly continuous development of 
the power through constantly rotating elements—as in the electric 
motor and the steam turbine—there must be reciprocating elements 
that function through indefinitely repeated series of operations. 
Such a series of operations is termed the cycle of the engine and is 
abundantly explained later in the book. It will suffice here to call 
attention to some of the merTs and demerits of the different cycles 
that are in practical use. 

Two-Cycle Engines. That type of internal-combustion engine 
in which every stroke in one direction is a power stroke affords a 
maximum of power impulses to any given number of engine revolu¬ 
tions, but because of other limitations it is not always possible to 
make a two-cycle engine run as fast as a four-cycle, so that in the 
majority of cases, the number of explosions in a given period of time, 
or for a given vehicle speed, is no greater with a two-cycle than with 
a four-cycle engine. 

In addition to this, most two-cycle engines are often difficult 
to start. They are likely to be wasteful of fuel, not at all flexible in the 
matters of speed and pulling power, and in various other respects 
difficult to apply to automobile service. Their greatest merit is 
their extreme simplicity. 

Four-Cycle Engines. The four-cycle engine is the type by 
which nine hundred and ninety-nine out of every thousand present- 




12 


GASOLINE AUTOMOBILES 



day automobiles are propelled. Varied through an immense number 
of possible forms, and with minor differences in the product of every 
maker, its fundamental functioning has, nevertheless, proved to be far 
the most suitable for automobile propulsion. 

With the succession of suction, compression, explosion, and 
exhaust strokes afforded by the four-cycle motor, a very positive 
and reliable functioning is secured; and by the expedient of a sufficient 
cylinder multiplication to afford good mechanical balance and fre¬ 
quent power impulses, its flexibility, durability, and practical quality 


Fig. 2. Eight-Cylinder V-Type Motor of Cadillac Car, Shown Installed in Chassis 

can be brought to a very high standard in a well-designed and honestly 
built motor. 

At the same time, the fact that so much more attention has 
been paid to the four-cycle motor than to any of its possible com¬ 
petitors for popular favor, undoubtedly accounts in some measure 
for its present pre-eminence, and it is an open question with many 
engineers as to just what virtues might or might not be realized 
with other constructions, were they as exhaustively experimented 
with and exploited. 

Cylinder Multiplication. There seems to be no reasonable limit to 
the extent to which cylinder multiplication can be carried in the effort 
to improve the mechanical balance and to even the torque of gasoline 
motors. But established practice has, nevertheless, settled upon 



















GASOLINE AUTOMOBILES 


13 


four-cyclinder vertical engines as those most suitable for the propul¬ 
sion of the average automobile, as this is the least number of vertical 
cylinders with which mechanical and explosion balance can be secured. 

The use of six cylinders, with the crank throws 120 degrees apart 
and the explosions occurring once for every 120 degrees of crankshaft 
rotation, affords a smoother-running motor than the four-cylinder. 

Still better than the “six,” from every standpoint except that of 
cost, which has prevented its wider application to automobiles, is the 
V-shaped, eight-cylinder motor, of the type illustrated in Fig. 2, 



Fig. 3. Overhead View of Stearns-Knight Eight-Cylinder Sleeve-Valve Motor 
Courtesy of F. B. Stearns Company, Cleveland, Ohio 


which gives a good view of the unit power plant of a well-known 
American machine. In both of these, a four-throw shaft, similar 
to the ordinary four-cylinder crankshaft, is used, is much cheaper to 
manufacture than a six-cylinder crankshaft, and the two rows of 
cylinders, each practically constituting a separate four-cylinder engine, 
are made to work upon the common crankshaft at 90 degrees apart. 

The most recent tendency in car motors is toward the eight-cylin¬ 
der V-type, following the marked success of this form in aviation use. 

Not only has the V-form been produced in the poppet-valve 
form, but also in the Knight sleeve-valve type an example of which 








14 


GASOLINE AUTOMOBILES 


is shown in Fig. 3. Furthermore, a considerable number of twelve- 
cylinder V-type motors have been built, a good example being shown 
in Fig. 4. 

An answer to the demands of the car owners for the flexibility 
and power of the multi-cylinder types has been recently given by the 
issue of a very flexible and quick starting four-cylinder motor with 16 
valves, two intake and two exhaust valves in each cylinder. Four 
of these of widely varying design have already been announced 
Stutz,White, and Drexel Motor Car Companies, and Wisconsin Motor 
Company. The details of the Wisconsin motor are given in the sec- 



Fig. 4. Side View of National Twelve-Cylinder V-Type Motor 
Courtesy of National Motor Vehicle Company, Indianapolis, Indiana 


tion on “Valves”. The large increase in the size of the valve openings 
makes clean mixtures and adequate scavenging easily obtainable, 
with a corresponding gain in the flexibility and power of the motor. 

In aviation work, no form of motor has made as great progress 
as the rotating-cylinder type, which has been built usually with an 
odd number of cylinders, as five, seven, or nine; or when these are 
paired with an even number, as ten, fourteen, or eighteen. As yet, 
this type has not been applied to motor cars, but considering its 
advantages, it would not be strange to see this done at an early date. 
These motors have a single-throw crankshaft of very light weight; 
the rotation of the cylinders at a rapid rate allows of their being air- 









GASOLINE AUTOMOBILES 


15 


cooled and also very light in weight, eliminating all of the parts and 
also the weight in the water-cooling system. The large revolving mass 
does away with the need for a flywheel, while the practical elimination 
of reciprocating parts reduces vibration to a minimum. 

In the extreme, motors of the V-type have been constructed with 
sixteen cylinders, eight in each group. These have been very suc¬ 
cessful in aeroplanes and motorboats, particularly the latter. 

GENERAL ENGINE TROUBLES AND REPAIRS 

Engine Troubles 

Deposits of Carbon in Cylinder. These are loosened by intro¬ 
ducing two or three tablespoonfuls of kerosene, put into the cylinder 
when warm through spark-plug hole. Replace the spark plug, but 
do not connect up the wires. Turn the engine over slowly to work 
kerosene back of rings. Allow it to stand a few minutes. Then 
connect the wires and start the engine running out of doors, as dense 
smoke will come for a time. Clean spark plugs and replace. 

Knocking. Knocking should not be permitted. It is likely to 
result in injury to the engine. Ordinarily, knocking is avoided by 
retarding the spark. In starting up a hill where considerable power 
will be needed, an open throttle with advanced spark should be 
employed before beginning the climb. Should the motor begin to 
knock when part way up the hill, the spark should be gradually 
retarded. Continued pounding is caused by the connecting rod and 
main-shaft bearings becoming loose. 

Failure to Start. Try the following remedies: 

See that current is switched on. 

See if throttle valve is open. 

Be sure gasoline tank is filled. 

Be sure gasoline valve is open. 

See that air can enter filling cap of gasoline tank. 

Flood carburetor. 

If weather is cold, prime cylinders by squirting a little 
gasoline in through each compression relief cock. 

See that spark plugs are clean. 

Missing of Explosions. See “Troubles with Ignition System.” 

Popping in Carburetor. Snapping or popping in the carburetor 
is caused by lack of gasoline, so that the mixture fed to the motor is 








16 


GASOLINE AUTOMOBILES 


not rich enough, and as a result it burns so slowly that one of the 
admission valves may be open before the charge is completely burned, 
and part of the burning charge is forced back through the pipe lead¬ 
ing from the carburetor to the combustion chambers. If adjustment 
of carburetor is such that a weak mixture should not occur, inspect 
the gasoline piping system carefully for an obstruction. Popping in 
the carburetor may also be caused by a leaky joint in the piping and 
bv connections between the carburetor and the combustion chambers. 

Poor Compression. Valve stem may be broken and sticking. 
Valve spring or valve stem may be clogged with dirt. Cylinder or 
explosion chamber may be cracked. Piston rings may be broken or 
turned so that cuts line up, allowing pressure to escape. Cylinder 
may be gummed. Cam may be loose. Water may leak into cylinder 
through plugs in cylinde r head. Valves may not seat properly due 
to being covered with soot. Valves may have to be reground. 

Engine Starts, but Stops, after a Few Revolutions. Engine bear¬ 
ings may have seized from lack of lubricant. There may be too 
much oil in crankcase. Water may be entering cylinder through 
cracks or through plugs in cylinder head. Carburetor float may be 
sticking. Poor water circulation may be due to broken pump shaft 
or clogged water piping. 

Engine Runs Well on Slow Speed but Not on High Speed. Muffler 

may be stopped up. Carburetor air valve not properly adjusted. 

Engine Pulls on High Speed but Not on Low Speed. There may 
be a leak in the inlet pipe. Carburetor adjustment not proper. 

Knocking Continues Even after Spark Is Properly Adjusted. 
There is a possibility of the flywheel being loose, of loose or worn 
bearings in the engine, or of something broken inside the engine. 

Repairs 

General Instructions. By far the most important part of the 
car is the engine, and this should, therefore, receive the greater 
portion of the time and attention during any repair or overhaul 
work, even by going so far as to take it out of the chassis if the trouble 
is at all serious. For this purpose, all ignition wires and carburetor 
and magneto operating rods are detached. Next, the various mani¬ 
folds are removed, the water system is drained, and all hose connec¬ 
tions are broken. Usually it is necessary also to take the radiator 


GASOLINE AUTOMOBILES 


17 





Fig. 5. Dismounting Engine for Repair 



Fig. d, 


Engine Dismounted, Showing Cylinders Removed 
















18 


GASOLINE AUTOMOBILES 


off. When this is done, the appearance of the vehicle and of the 
work is very much like that presented in Fig. 5, which shows two 
men engaged in loosening up certain parts of the engine preparatory 
to taking it out. 

When all accessories have been removed or loosened up, the 
holding bolts are taken out, the clutch disconnected, and the motor 
is left free to be swung out by means of a small crane or hoist. In 
some cases, the work can be completed without disturbing the base 
of the motor, as in Fig. 6, which shows a big car partly disassembled 
for repairs, the radiator and cylinders having been removed at this 
stage. The trouble here was found within the cylinders, hence, 
as soon as they had been removed, the balance of the six-cylinder 
motor and its chassis could remain undisturbed. 

Hoists and Cranes. Yale & Towne Form. For lifting out an 
engine or other unit approximating several hundred pounds (possibly 

500 pounds in the case 
of a big engine) an effi¬ 
cient form of overhead 
hoist is needed. There 
is nothing better than 
the Yale & Towne 
triplex hoist, although 
this is not a cheap form. 
It can be attached to 
any channel or I-beam 
built into the roof of the building, or if that is impossible, it can be 
hooked into any wire or rope loop over a ceiling beam. It multiplies 
the power which one man can apply to such an extent that one man 
can lift out a 500-pound engine with it very readily. 

Home-Made Ceiling Iloist. Lacking one of these, a substitute 
can be made as indicated in the sketch, Fig. 7. The track is plain 
rectangular metal, known as J inch by 2 inches flat, while the brackets 
supporting it can readily be forged by any good blacksmith. The 
trolley consists of a forged and bent arm for one side and a 
straight bar for the other. Fhe wheels can be found in any hardware 
store. The bottom end should be drilled and tapped, and the ring 
made in the lathe to fit into it. For this purpose, the threads should 
be large and numerous. The ring could be forged integrally, but that 



Fig. 7. Method of Constructing Track Attached to 
Ceiling of Shop 































GASOLINE AUTOMOBILES 


19 


would complicate the job. When hung, any crane, hoist, or any block 
and tackle, can be hooked into it and when the load has been lifted 
clear, it can be run along the track until the desired point is reached. 

If this expense is too great, the same results can be obtained 
by taking a sliding-door track and suspending it from the ceiling 
beams. Then the two door carriers can be joined by the large end 
of a V-shaped piece of steel, not less than \ inch by 2 inches in section; 
while the carriers are separated and held separated by a simple straight 
distance piece. The lower end, or point of the V, supports the 
hook or eye, whichever is used. That is, from an old sliding door, 



Fig. 8. Overhead Support and Trolley, Used When Roof Trusses Are 

High or Weak 


a traveling hoist can be constructed easily and quickly to handle 
engines or other large and heavy units. 

Floor Type of Hoist Support. When the construction of the roof, 
or ceiling, is such that it will not permit a suspended hoist, one which 
works from the floor can be constructed. This consists, as Fig. 8 
shows, of a double track beam supported on castor-mounted triangu¬ 
lar ends, which extend as high as the garage will allow. By this 
means, the weight can be lifted clear, and the entire structure moved 
to the desired place. It is constructed a good deal like those just 





20 


GASOLINE AUTOMOBILES 


described; the ends are fair sized angles, say 2 inches by 2 inches 
by inch; the braces lighter stock, say 1J inches by 1J inches by 
inch; and the castors are anything that is available. It is not 
necessary that the track be metal; wood can be used if it is wide 
enough to withstand the wear of the wheels and deep enough to 
carry the heavy loads. 

Commercial Forms. If sufficient money is available to purchase 
a hoist, these makeshifts are, of course, unnecessary. There are a 
number of portable cranes for garages on the market, costing from $90 
up. These usually have a U-shaped base of heavy cast iron with 

two castors at the points, and one 
at the back of the U. At the back 
also is a vertical pillar about 6 
feet high, with a curved exten¬ 
sion. At the end of the extension 
is a grooved pulley carrying a 
chain hoist. The crane runs back 
to a sheave and set of gears for 
winding it up. It has a suitable 
handle for this, as well as a long 
folding handle for moving the 
crane around. Among those 
available are: the Champion, 550 
pounds shipping weight, of f-ton 
capacity, with a lift of 4 feet 8| 
inches; the Franklin, which will 
lift 2000 pounds, and weighs 480 
pounds; the New Jersey, which will lift 6 feet 8 inches, weighs 600 
pounds, and has a capacity of 2000 pounds; the Canton, which will 
handle 2000 pounds, and lists at $100; the Hilite, which is built in 
two capacities and four different lifts; and others. 

Form of Cradle. Many times, even with a suitable crane or hoist, 
it is necessary to make a cradle for the motor because of difficulty in 
attaching the chains or ropes to it, difficulty of balancing it safely, 
or for other reasons. A cradle for a six-cylinder motor is seen in Fig. 9. 
This is, of course, applicable only to this particular motor, but in a 
shop handling one car continuously, there is enough saving to warrant 
making such an outfit. The four bars are made from two pieces of 


ix2"5tee! 



Fig. 9. Sling for Engine Which Saves Much 
Time in Attaching 





















GASOLINE AUTOMOBILES 


21 


round stock, put through the drilled holes in the upper or supporting 
bar, then bent over and shaped. Before anything is done, the ends 
of the bars must be turned down and threaded. In this instance, 
there is a hole at the four points on the shelf of the motor, so these 
holes govern the size of the ends of the rods and also their spacing. 
On almost every motor, there will be some means of attachment which 
can be studied out in advance, and the rig built to fit it. 

Portable Engine Stands. If the engine is removed from the 
chassis, the first thing needed is a suitable engine stand. One of these 
is shown in Fig. 10, a form that can be purchased at a reasonable 
price, and which possesses many excellent features. The frame is made 


Fig. 10. Handy Form of Engine Stand Constructed from Piping 
Courtesy of Shewalter Manufacturing Company, Springfield, Ohio 



of tubing, which gives a maximum of strength in a minimum of space. 
The oil drip pan beneath is a good feature, as is the shelf arrangement 
at the open end. The large castors allow it to be moved around readily 
and can be clamped to hold it any place. One can be constructed 
out of heavy galvanized pipe and pipe fittings at a moderate cost. 

This form of engine stand holds the motor in its natural, or upright, 
position. But it is not always desirable to have the engine in that 
position; in fact, when working on crankshaft bearings and other parts 
on the under side, it is necessary to have it inverted. There also is 
work which makes an intermediate position desirable. For this 
purpose, an engine stand is needed which can be turned to any desired 




22 


GASOLINE AUTOMOBILES 


angle and fastened there. Such a stand is shown in hig. 11, which 
represents one made by the International Motor Company, Plainfield, 
New Jersey, for its own use. It would hardly pay to make one of these, 
as the ends are castings which require a pattern, but if a couple of 
garages wanting, say two each, would go in together, it would pay to 
have patterns made for the four. After making castings for their own 
frames, the garage owners could later make them for sale if they 
wanted to go into the business. The sketch explains the construction, 
but this explanation might be added: the central part, projecting from 



Fig. 11. Engine Stand Which Allows Motor to Be Turned to Various Positions 

the left-hand member is attached to the rear crankcase arms, and 
when the engine is turned, this turns with it. The central rotating 
member on the upper part of the right-hand unit is made to take the 
starting crankshaft, and the clamp at the upper left is to lock it in 
the desired position. Eight holes are provided, but a person making 
one could have as many as he wished, since they are drilled. As will 
be noted, there are six pieces, but the two bases are made from the 
same pattern, so five patterns are all that would be needed. 

CYLINDER AND CRANKSHAFT SUB=GROUP 

CYLINDER FORMS AND CONSTRUCTION 

Materials Used. Gasoline-engine cylinders are variously made 
of cast iron, cast steel in the form known as semi-steel, forged steel, 
aluminum alloys, and other materials. For durability, and the ability 
to withstand high temperatures without warping, nothing has been 
found superior to cast iron, even though the lightness of steel and of 





















































































GASOLINE AUTOMOBILES 


23 



aluminum alloys has commended them for aviation use and in some 
cases for racing automobiles. 

Method of Classifying Cylinder Forms. Cylinders are generally 
named according to two things: first, the method in which they are 
cast or produced; and second, the shape of the combustion chamber, 
or arrangement of the valves. Thus, according to the first method, 
they are divided into those which are cast separately, that is, each 
cylinder by itself; cast in pairs, or each two cylinders cast together; 
cast in threes, a modern modification fitted to the six-cylinder engine; 


Fig. 12. Typical T-Head Cylinder Units with Other Cylinder Parts 
Courtesy of Locomobile Company of America, Bridgeport, Connecticut 

and cast together, or en bloc, that is, all of the cylinders cast as a 
single unit. 

According to the second method of naming, cylinders are of the 
L-head type, in which the combustion chamber has the shape of an 
inverted capital letter L, formed by the placing of all valves on one 
side; of the T-head type, with the combustion chamber shaped like a 
capital T, because the valves are equally distributed; of the I-type, 
or valve-in-the-head type, so called because the combustion chamber 
is left perfectly straight and round by placing the valves in the head; 
and modifications of these. 





24 


GASOLINE AUTOMOBILES 


Usually in speaking of the cylinders, both names are used as one, 
as, for instance, those of Figs. 2, 3, and 4, all of which happen to be 
alike, would be spoken of as L-head blocks, Figs. 12 and 13 as T-head 
pairs, etc. 

Methods of Casting Cylinders. Cast Separately . The early and 
still common practice in the building of multi-cylinder gasoline motors 
is the casting of cylinders separately. This policy makes it easier to 
secure sound castings, simpler to machine and finish them, and less 


Ignition Cable and Cable Tube 


Spark Plug 
Valve Cag 

Intel Manifold 


Cylinder Cover 

'Combustion Chamber 

Piston 

Cxhaust Valve 


Inlet Valve Spring 
Governor Housing 



Main Frame 


Piston Rings 

"jo, Hochaust Manifold 
A' ^ Piston Pin 

Connecting Rod 

Water Pipe Inlet 
to Cylinders 

Cylinder 
Water Pump 


Intel Valve Tappet 
Intel Cam Shaft and Cam 
Crank Case Oil Duct 
Oil Pan Oil Duct 


Czoos Section or Engine 


Crank Shaft 
Oil Pan 
Oil Troughs 


Fig. 13. Section through Locomobile Cylinder Shown in Fig. 12 

troublesome to disassemble parts of the motor without disturbing 
the rest. y 

In a number of cases, where extremely light weight was desired, 
this method was followed, but the cylinders were machined all over 
and a sheet-copper water jacket was applied in assembling. This has 
been most successful in aeroplane work and also for motor cars, but 
when the Cadillac changed to the form shown in Fig. 3, this construc¬ 
tion lost its principal American adherent. In addition to this con¬ 
struction, there have been a number of motors built with an applied 


































































































































































GASOLINE AUTOMOBILES 


25 


water jacket of sheet metal of the built-on form. These have shown 
splendid cooling abilities, but, under the twisting and racking of 
automobile frames, particularly in later years, with the use of more 
flexible frames, they have shown too much tendency toward leakage 
to become popular. 

Cast in Pairs. Just as soon as two-cylinder and four-cylinder 
engines were produced, the cast-in-pairs form of cylinder appeared 
and is almost as widely used today as then. While the modern 
tendency toward smaller bores, compactness, and light weight has 
greatly increased the number of cylinders cast en bloc, the paired 



Fig. 14. Studebaker Six-Cylinder Motor, Showing Block Castings of the Six Cylinders 


form, including the cast-in-threes modification for six-cylinder 
engines, holds its own. 

Cast Together. The great advantage of having the several 
cylinders of one motor cast together —en bloc, as the French term it 
is that the alignment and spacing of the different cylinders is thus 
rendered absolute and permanent, regardless of any differences in 
adjustment that may otherwise occur in assembling. 

This construction has been applied to a large proportion of the 
small and of the medium-sized fours, a fair proportion of the larger 
fours, and to a considerable number of sixes, Fig. 14. 











26 


GASOLINE AUTOMOBILES 



O U u 

rj) <•» 'S' rf; 




V — 

L£. U 


...IN . 


u 
6 o 


\2 _2 _3 
O V O 


Fig. 15. Part Section of Ford Motor 
In this engine cylinders are cast together 



































GASOLINE AUTOMOBILES 


27 


Another advantage is, that the water connections, exhaust and 
intake manifolds, etc., are rendered simpler both in their form and 
the number of their points of attachment. 

In some advanced motor designs, the passages for the incoming 
mixture and for the exhaust gases, and in one case even the carbu¬ 
retor itself, are all incorporated in the main casting. 



Fig. 16. Section through Typical L-Head Cylinder with Valve 

Parts in Place 

Courtesy of the Hudson Motor Car Company, Detroit, Michigan 


Another example of simple construction is that illustrated in 
Fig. 15, which depicts one of the latest Ford motors, in which cylin¬ 
ders, upper half of the crankcase, and the gearbox are all cast in one 
piece. The lower half of the crankcase and gearbox are similarly 



















































































































28 


GASOLINE AUTOMOBILES 


constituted of another simple pressed steel unit, while a second casting 
is used for the heads of the cylinders and for the water connection. 

Cylinders Classified as to Fuel Chamber or Valves. L -Head 
Forms. In the L-head form, the valves are all located on one side, 
and usually because of this, all the accessories are on the same side. 
This makes a lop-sided engine, with carburetor, inlet pipe or manifold, 



magneto and wiring, exhaust 
manifold, and sometimes elec¬ 
tric generator and other parts 
all grouped on one side, with 
little or nothing on the other. 
While a disadvantage in four- 
and six-cylinder motors, this 
is somewhat of an advantage 
in eight- and twelve-cylinder 
forms, for all the parts and 
auxiliaries can be grouped in 
the V between the cylinders, 
leaving the outside clear. On 
the other hand, where this 
grouping has been found unde¬ 
sirable for four- and six-cylin¬ 
der motors, it has been possible 
to overcome it in part by taking 
the magneto and carburetor 
over on the other, or plain side, 
of the cylinders, leading a con¬ 
duit back for the wires in the 
one case, and a long inlet mani¬ 
fold in the other. An L-head 
cylinder is shown in Fig. 16. 


T- Head Forms. A desire 
for more symmetry and a better arrangement has brought about the 
T-head form, which has the inlet valves, carburetor, and inlet mani¬ 
fold on one side, and the exhaust valves and manifold on the other. 
This separation gives more space on both sides, and allows the dis¬ 
tribution of the other engine accessories so that each has more 
accessibility. This is important, for some parts, like the magneto, do 










































































GASOLINE AUTOMOBILES 


29 



Fig. 18. Typical Arrangement of Overhead Valves of Interstate Motor 



Fig. 19. Aluminum Casting for Cylinders and Upper Half of Crankcase in Marmon Engine 
























30 


GASOLINE AUTOMOBILES 




Hard Cost Iron Sljaeva 
fzocuroie iy Of round y 


■5leevs If eld in F 


not withstand the heat well, and consequently should be far away from 
the heat of the exhaust manifold. See Figs. 12 and 13. 

I- Head Forms. The valve-in-the-head, or overhead valve, motor 
requires an I-head cylinder, because, with this location of the valves, 
tnere is no necessity for the valve pockets of the other forms. Con¬ 
sequently the cylinder can be straight and plain, while the head, 
which is separate, is fastened on instead of being cast integrally. 
It may have either the L- or T-form, according to the location of the 
valves and the inlet and exhaust manifolds. Fig. 17 shows an I-head 

in which the manifolds are 
located on the opposite side. 
Note that in this form the 
cylinder head is integral, the 
valves being set in cages 
which are removable, as 
shown in the view of the 
Interstate Motor, Fig. 18. 

The forms are not so 
clearly separated as they 
were formerly, for the inclu¬ 
sion of cylinder heads in one 
case, and their exclusion in 
another; the integral casting 
of manifolds, water passages, 
etc.; the casting of crankcase 
upper halves and also of gear 
covers, flywheel enclosures, 
transmission cases and other 
parts, all of which are quite common; no longer leave the cylinder 
casting as a single simple clear-cut unit. 

A marked example of this is seen in Fig. 19, in which the six 
cylinders, with water jackets and water passages, and the upper half 
of the crankcase are cast as one. The detail of this, shown in Fig. 20, 
indicates the cast-iron sleeve, inserted to form the long-wearing 
cylinder bore within the aluminum structure, which is easier to cast 
in this complicated form. To a certain extent this modifies what was 
previously said on the subject of materials, for in this case the material 
of the cylinder is not of one but of two kinds, cast iron and aluminum. 


Fig. 20. Detail of Marmon Cylinders Showing Cast- 
iron Sleeves Inserted in Aluminum Casting 














GASOLINE AUTOMOBILES 


31 


Cylinder Repairs 

s. 

Removal of Carbon. One of the things every repair man must 
do is remove carbon. A good method is the introduction of a metal 
object, as a ball or a piece of chain, which the piston is allowed to 
bounce up and down to break up the carbon. This is successful, 
but there is always the danger of the part getting under a valve or 
other part, and causing trouble. 

A better way is to couple up a number of short lengths of chain— 
old tire chains will do—and attach them to the flexible shaft of a 
buffing or polishing outfit, as shown in Fig. 21. This chain and 



Fig. 21. Removing Carbon with Flexible Shaft and Old Chain 
(A) Motor, Shaft, and Chain; (B) Method of 
Assembling Chain; (C) Device in Use 


shaft end can then be introduced into the combustion chamber 
and, when the current is turned on, the rotation breaks off all carbon. 

Carbon on Fixed Cylinder Heads. When the motor has fixed 
cylinder heads, and the valve opening is small, this is not always a 
good way. Another somewhat similar tool can be constructed to go 
in through the bore of the cylinder and clean off the cylinder head very 
nicely. This is shown in Fig. 22, at work (at right) and in detail 
(at left). It consists of a round steel brush with very stiff wire 
bristles mounted in a four-cornered frame. The latter should be 
smaller than the cylinder bore by \ inch or so, but the bristle 



































































32 


GASOLINE AUTOMOBILES 


circle should be full diameter. When rotated by means of a flexible 
shaft, the outside bristles have a tendency to throw outward, so that 
this device will clean a space considerably larger than its diameter 

when at rest. 

When the electric 
motor, or electricity tc 
furnish power for the 
device shown in Fig. 21 
is not available, similar 
results can be obtained 
by attaching a geared 
hand drill, as shown in 
Fig. 23. When this is 
used, however, it is diffi- 
Vlt to attain sufficient 
speed to expand the 
chain, so a wire brush 
with fairly long wires 
will be found better 
suited. Several sizes of 



Fig. 22. Steel Wire Brush and Flexible Shaft Method of 
Removing Carbon from Cylinder Heads 



/ 


Fig. 23. Removing Carbon from Cylinder Head with Brace and Wire Brush 























































































































































GASOLINE AUTOMOBILES 


33 


Hir Sup ply 


wire—long, short, and medium—will come in handy, also brush ends 
with various diameters of shank, with copper tubing around the 
actual shaft, or flexible tubing. This can be inserted more readily 
than the chain “mop” shown in Fig. 21. But, as stated above, it 
cannot do equal work, because it cannot be revolved so fast. 

Compressed Air. If the cleaning periods for the engine are not 
too far apart, the greater portion of the carbon can be blown out with 
compressed air by using the air after a chain “mop” or wire brush 
just described. To use the air, however, calls for a special fitting, 
two of which are shown in Fig. 24. The one at the right is the most 
simple, but the one at the left has the advantage of being made from 

i ■. 

pipe fittings instead of from brass tubing. Both screw into the opening 
in the center of the cylinder head, and the air enters through the 
central hole, while the r 
carbon is blown out 
through the larger annu¬ 
lar opening. 

Liquid Solvent. 

Nowadays, carbon re¬ 
moval is often accom¬ 
plished by means of liquid 
solvents. Of these, ker¬ 
osene, denatured alcohol, 
and special preparations 
are the most widely known and used. Kerosene is used when return¬ 
ing from a trip. Just before stopping the engine, it is speeded up 
and a little kerosene inserted into each cylinder. This loosens the 
carbon so that it blows out through the exhaust. 

Denatured alcohol and also the special preparations are used 
in much the same way, except that the engine is not run. After 
returning to the garage, and while they are still hot, an ounce or so is 
placed in each cylinder and allowed to stand there o\ or night. On 
starting the motor the next morning, the loosened carbon is blown 
out through the exhaust pipe. If the carbon is very thick, more 
alcohol must be used and allowed to stand for a longer time. By 
repetition, this will gradually clean out all there is in the cylinders. 

Removing Carbon by Scraping Tools. When all other means of 
removing the carbon fail, the repair man must go back to hand 









' - 










Fig. 24. Set-Up for Blowing Out Carbon from Cylinder 
Heads after Loosening 








































































34 


GASOLINE AUTOMOBILES 



scrapers. In any case, these are the most simple and fully as 
effective as any; provided the extra time needed to use them and do a 
good job is available. When the offending member has been brought 
out so it can be handled, the removal of the carbon can be accom¬ 
plished in a few minutes. A flat piston head, like that shown in 
Fig. 25, can be scraped off with any knife or chisel, but a special 
scraper made from an old file, flattened out at the end, and ground 
down so as to present one sharp edge is better. Every garage man 
should accumulate from five to a dozen shapes and sizes of scrapers 


Fig. 25. Removing Carbon with File 

for various work, including a flexible one with which to reach into 
corners. The carbon is brittle and comes off readily. After its 
removal the surface should be filed or rubbed over with emery and oil 
to make it smooth, in order to delay the formation of a second coat. 
This is true of carbon in other places, but usually it is impossible to 
smooth the surface, in which case the process must stop when the 
part is scraped clean. 

A number of excellent plain and special forms of scrapers which 
the average garage should have are illustrated in Fig. 26. The one 


Made 
Old File 

Surface, 


Girbon Deposit 










GASOLINE AUTOMOBILES 


35 


at the top, A, is a plain straight scraper with a hooked end. Where 
there is plenty of room to work, this is the usual tool. That at B is 



Fig. 26. Various Types of Carbon Scrapers 


somewhat similar, except that the length is greater, and the end is 
bent. This allows of getting up or down further than with the straight 
tool. A form with a double bend, no handle, and a scraper at each 
end is shown at C. The advantage of this lies in getting around 
curves and corners. Still another at D has the same curves and a 
similar double curve in the other direction; this also allows working 
into deep corners. That indi¬ 
cated at E, with a shape like a 
hoe, is made that way to conform 
to the upper curved surface of the 
ordinary combustion chamber and 
the flat top of the piston. The 
handle screws in, and to insert the 
tool in the motor, it is taken 
apart, and parts put in through 
separate holes and assembled or 
screwed together inside. The 
form at F is particularly suitable 
to the eight-cylinder Cadillac 
cylinder head, but may be used 
with any motor having a similar 
design. It is a rotary form, the 
central plug being screwed in, to replace the cylinder-head plug. 
The rotation of the handle outside causes the tool inside to turn 































































36 


GASOLINE AUTOMOBILES 



around over the surface of piston top and combustion chamber. 
When used against the top it is pulled upward. It is pressed down 
when used against the bottom, or the piston. Other special forms 
will be constructed by the clever workman for certain motors having 
peculiarities which make these specials desirable and time-saving. 

Compression Indicating Gage. Before taking off the cylinder to 
look for trouble inside, the repair man should do all he can to find out 
what and where the trouble is. A compression gage is handy, as 
this indicates the pressure in each cylinder. These should all agree 


Fig. 28. Using Stethoscope to Listen to Engine Noises 

when the motor is right, but if pistons or rings are not right, or if the 
cylinder is scored, the gage will show a lower figure than the other 
cylinders. Such gages can be purchased or can be made from old 
materials on hand; as, for instance, that shown in Fig. 27, which was 
made from an old spark-plug shell and a tire gage. The stem of the 
latter was set inside the shell and firmly fixed there by means of 
babbitt after both were scored so the metal would take a firm hold. 
Whenever a motor acts peculiarly, the spark plug is removed from 
each cylinder in turn, the home-made gage inserted, and the reading 
noted (with the motor running or being turned over by hand). 
Many times leaky valve pistons or valve-stem guides will cause a miss 








GASOLINE AUTOMOBILES 


37 


which nine persons out of ten would blame to the carburetor. This 
gage will show up these leaks. 

Locating Noises by Means of a Stethoscope. Besides this, it 
should be borne in mind that there are many sources of noise in 
and on the engine other than that produced by valves and valve 
motions. In fact, the noises made by the valves, while an indication 
of loss of power, do not represent anything like the possibilities for 
trouble indicated by a piston slap, a crankshaft or connecting-rod 
pound, the whirr of worn timing gears, and others. In order to locate 
such sources of noise exactly, at a time when the beginner lacks famil¬ 
iarity with the motor and its troubles he should purchase or borrow 
and learn to use a stethoscope, Fig. 28. A modification of the sur¬ 
geon’s well-known instrument is now made for use in automobile 
trouble finding. 

The stethoscope, or its modification, simply magnifies all noise; its 
construction is such that one end is held against the suspected part, 
while the other end constitutes an ear piece. When the engine begins 
to make a great deal of noise, particularly heavy pounding noises, this 
should be brought into play. With the motor running, place the free 
end against the various parts of the engine, going slowly from one 
to another. In this way it will soon be found where the trouble lies. 

A piston slap is not so easy to define or so easy to repair. It 
may be called a noise which comes from within the cylinders, trace¬ 
able to the pistons, or to one piston, as the case may be, which 
sounds very much like a shaft pound, except that it is a louder noise. 
It occurs when pressure is put on the piston, as at the beginning of 
compression, at the time of explosion, or at times at the end of each 
stroke. It is said to be due to different causes. Some say it is 
caused by a loose piston pin, but the writer knows of two cases in 
which a new tight pin left the piston slap just as clear and distinct 
as before. Others say it is caused by rings which are loose up and 
down in their grooves, but in the cases above, new rings which fitted 
tightly in this way did not help any. It has been ascribed to a piston 
which was out of round, so that it did not fit the cylinder, and also to 
a groove and shoulder having been worn in the cylinder surface, the 
piston striking this each time. Whatever is the real cause, and the 
writer is inclined to blame it to a poorly fitting piston, nothing will 
really remedy it but a new piston, complete with rings. 


38 


GASOLINE AUTOMOBILES 


Making Gaskets. Anyone who is going to do much repair work 
will soon have to learn the art of making gaskets, for, in almost every 
ease, the removal of a paper gasket is accompanied by its breakage, 
so it is rendered unfit for further use. A gasket, it might be explained, 
is a formed sheet of heavy paper, cardboard, or special material fitted 
between two surfaces of a joint which must resist the leakage of gases 
or liquids under pressure. By means of the bolts or screw threads 
which hold the two parts of the joint together, the gasket is com¬ 
pressed and, in its compressed state, it resists the internal pressure. 

The following method of making gaskets applies alike to round, 
oval, and odd-shaped ones, which cannot be said of special tools and 

fittings for gasket cutting: Select 
a good piece of heavy brown 
wrapping paper or special gasket 
paper without too many wrinkles, 
and free from cracks or flaws. 
Clamp the part for which the 
gasket is to be made in a vise to 
steady it and lay the paper over 
it. Then go around the edges 
of the part, tapping lightly on the 
paper with the flat face of a ham¬ 
mer, holding the paper in position 
meanwhile with the other hand. 

This method is illustrated in Fig. 29, where a workman is shown 
making a gasket for the base of a cylinder. In this particular 
instance, holes must be made through the gasket for the cylinder 
bolts. These are made with the round or peen end of the hammer 
or with the punch. When made, the punch is stuck into the hole to 
help hold the paper steady. In this case, too, it was necessary to cut 
the inside of the gasket out first, then this material (the paper from the 
inner or smaller hole) was removed, the sheet put back in place on 
the base of the cylinder, and work started on the exterior cutting. 

If the hammer be held at a sharp angle with the edge of the 
part for which the gasket is being cut, each blow will cut through, 
or partly through, the paper. By repeating this operation enough 
times, going around the part meanwhile, the result is the finished 
gasket which will fit the desired place exactly. 



















GASOLINE AUTOMOBILES 


39 


Cylinder Heads. A great many motors have detachable heads, 
and their quick removal is a great convenience, when there is carbon 
to be scraped off, pistons to be looked over, or other internal work 
to be done. However, replacing them is never quite so easy as 
removing them, partly on account of the cylinder heads themselves 
and partly on account of the pistons. The latter are particularly 
troublesome when the cylinder head is hinged. The cylinder head 
should be replaced with great care, and after replacement it is fully 
as important to bolt it on properly. 

If one bolt or a series of bolts is 
tightened too quickly and too hard, 
it is likely to result in cracking the 
cylinder casting or the head casting 
or both. 

Proper Method of Bolting on 
Head. Usually, on an L-head type 
of motor, there are three rows of 
bolts for the cylinder head—one row 
along the middle, screwing into one 
side of the cylinders; another row 
screwing into the other side of the 
cylinders; and a third along the valve 
side. These should be tightened in 
order: first the middle bolts of the 
middle line, working out to the ends; 
next in turn, the middle bolts of the 
back of the cylinder, the middle bolts 
of the valve side, the ends of the 

Cylinder; and finally, the *md bolts on 3 Q Construction of Simple Rig for 

the valve side. All these should be Measuring Worn Cylinder Bores 

tightened but a few turns at a time, and after all are down, a 
second round should be made in about the same order, to give 
each bolt a few more turns. In this way the cylinder head casting, 
which is both large and intricate, is slowly pulled down to the 
cylinder straight and true so that it is not warped or twisted. More > 
over, if the cylinder is pulled down straight in this manner, all the 
bolts can be tightened more than if the first bolt were tightened very 
much, for the latter would result in cocking up the opposite side. 


































































40 


GASOLINE AUTOMOBILES 



Checking Up Cylinder Bore. Before any work is done upon the 
cylinder bore, such as turning, grinding, etc., it should be checked up 
very carefully. An expert workman, accustomed to the tool, would 
use an inside micrometer, but when this tool is lacking, as well as the 
experience necessary to use it, a fairly simple tool which can be used 
by almost anyone may be constructed as follows: As shown in Fig. 30, 
a short angle iron forms one side of the bore-measuring part; its length 
is sufficient to keep the entire tool perfectly vertical when the cylinder 
is vertical, and thus gives an accurate right-angle measurement of the 
bore. A central arm is fastened to this and the framework adjustably 


Fig. 31. Grinding Engine Cylinders 

View Shows Exhaust for Dust, Jig for Holding Cylinders, and Eccentric Wheel Spindle 
Courtesy of Heald Machine Company, Worcester, Massachusetts 

bolted to it. This includes the indicating dial at the top. At the 
lower corner is the indicating member, which is simply an L-shaped 
piece with a very short base and a very long stem; this is pivoted at 
the center of the bend. It is held against the side of the cylinder by 
means of a light spring. After adjusting the tool to the approximate 
cylinder bore, it is inserted, and a reading is taken; the tool is then 
moved, and another reading taken. The length of the arm is so 
great that any movement of the small arm is magnified about 15 
times. In this way a difference of ToVo in the bore shows as tmi 
on the dial, or wt. In a shop where most of the work is on one motor, 











GASOLINE AUTOMOBILES 


41 


the micrometer could be improved by eliminating the adjustable 
feature and making the frame and angle face a solid piece. 

Grinding Out Cylinder Bore. As the usual amount of metal 
which would be removed from a worn cylinder would not exceed a few 
thousandths of an inch, grinding should be the process used. Other 
processes, except possibly lapping or hand grinding, are too inaccurate. 
For this reason, a typical grinding set-up is shown in Fig. 31. This 
shows the cylinder bolted against a large angle plate, attached to the 
grinding machine table. The angle plate is drilled out to take the 
bolts which hold the cylinder casting to the crankcase. When bolted 
up for work, the air hose is connected up through the cylinder head 
to blow out the dust or particles ground off. Not more than three or 
four thousandths of an inch should be taken off at one time; if more 
must be removed, a second operation over the surfaces is necessary. 

If the cylinder is worn badly enough to warrant re-boring, which 
calls for new pistons and rings, it should be borne in mind that a 
standard set of oversizes has been adopted by the Society of Automo¬ 
bile Engineers, and that all manufacturers are working to them, by 
stocking pistons and rings according to these dimensions: 


Oversize Standard 
For 1st Oversize 
For 2d Oversize 
For 3d Oversize 
For 4th Oversize 


Inches Large 
10 thousandths (.010") 
20 thousandths (.020") 
30 thousandths (.030") 
40 thousandths (.040") 


Methods of Cylinder Lapping. When the cylinder must be 
lapped or ground out to a true surface, not re-bored, and when no old 
piston is available for 
this purpose, there are 
several methods avail¬ 
able. One is to use a 
standard lead lap, that 
is, a solid round bar of 
cylinder size. The abra¬ 
sive may be either emery Fig. 32. Home-Made Lapper for Cylinder Bores 
17 (Note Spiral Grooves) 

and oil, carborundum 

dust and oil, or, in some cases, ground glass and oil imbedded in 
the soft surface of the lead^ yet it projects enough to abrade the 




42 


GASOLINE AUTOMOBILES 


cylinder surface a little at each revolution. Another good way of 
doing this is to use a round block of wood, as shown in Fig. 32. This 
is made a close fit in the cylinder, with spiral grooves cut in its surface, 
and a split along one side. Into the latter a wedge is driven to adjust 
for wear. The emery and oil is put on the surface, and the lapping is 
done as usual. The spiral grooves distribute the abrasive evenly so 
that a true surface results. 

Another way of doing this is to make a large special boring bar, 
say 2 inches in diameter, and drill a hole into this at right angles. 
Then, a small round section of carborundum, say \ inch in diameter, 
is placed in this hole with a spring back of it to keep it up against its 

work. This arrangement can 
be used on a lathe, the bar 
being rotated in the usual way, 
and the cylinder fed up to it 
either by the carriage feed or 
by hand. It will give a very 
fine cylinder surface, and use 
up very little of the carborun¬ 
dum, which costs very little to 
begin with. The advantage 
of this method is that the 
same outfit can be used on 



Fig - 33 ' Dead Sr man y different sizes of cylin- 


ders. 

Simple Dead Center Indicator. In a great deal of engine work, 
it is necessary to know when the pistons in the various cylinders are 
on dead center, either the upper or the lower center. For this 
purpose a form of indicator which is simple, easy to use, and accurate, 
is needed. A good one is shown in Fig. 33. This consists of nothing 
more than a §-inch steel wire, or narrow steel strip, bent to the form 


shown. It is indicated as setting into one cylinder of an eight- 
cylinder V-type motor, but with slightly more bending it is applicable 
to any form of V-type or vertical cylinder motor. The bent end is 
inserted, and the engine gradually turned by means of the crank until 


the tip end of the wire extending from the cylinder stops moving. 
This point is the upper dead center, and the lower center is found 
.similarly. The advantage of the shape shown and of the long 





GASOLINE AUTOMOBILES 


43 


extended end is that a very minute movement of the piston is mag¬ 
nified and shown as a considerable movement at the end of the wire. 
Thus, it is possible to determine the dead center point very exactlv. 

Repairing Cracked Water Jackets. Very often the first cold 
spell of fall will catch the owner napping in the matter of heat for 
his motor, and will freeze up the water, which finds a weak spot in the 
water jacket and cracks it. When the crack is small and localized, 
it can be repaired very simply as follows: Drill each end of the crack 
as shown at A and B, Fig. 34, and screw in small f-inch brass plugs to 
prevent the crack from spreading. Then cut back the outer sides 
of the crack with a small cold chisel to permit inserting a considerable 
amount of rusting compound, being careful not to cut away any 
quantity of good metal. Then fill the 
crack up very fully and carefully with 
the compound consisting of two parts iron 
filings and one part sal-ammoniac. Just 
enough water should be added to this to 
make a paste which can be handled better 
than the dust or powder. After inserting, 
let tL? cylinder stand for a day or two, 
and if it does not seal up quickly and 
entirely, add a little water. If this does 
not complete the job, it may be necessary 
to go over it again, adding more of the 
rusting compound. After a couple of tries, 
almost any skillful repair man will get the hang of this job, and be 
able to seal a water jacket crack perfectly every time. 

Welding Breaks in Cylinders. Welding is used very frequently 
now on cylinder breaks, probably more than any other method, since 
it has proved to be quick, accurate, and cheap. It has all the 
desired qualities, which cannot be said of any other process. More¬ 
over, it can be used with almost any form of metal, which also cannot 
be said of any other method. A separate chapter deals with welding, 
very exhaustively. It is recommended that every repair man study 
it; then get an outfit and learn to use it, for it represents a source of 
large profit when its use is once mastered. With a welding outfit, 
the method of procedure is often the reverse of other processes. Thus 
when a water jacket is cracked, the first operation is generally the 







44 


GASOLINE AUTOMOBILES 


cutting away of sufficient metal to enable the workman to see the 
whole extent of the crack and also to permit getting at all the surface 
with the welding torch. With a crack of small size, such as that just 
described, enough of the sides should be cut away to allow working 
the torch in between them. This crack should be gradually refilled 
with new solid metal, melted in from a fuse bar or melt bar. The 
sides should be cut away so as to take off more on the inside if possible, 
as this gives the new metal a natural hold on the inside in addition to 
the fusing together of the old and new metal. 

When the crack is larger, but still not a big one, as a small curved 
or circular shape, say 2 inches long, a formed steel plate can very often 
be cut which exactly fits around and over the crack. This is then 
welded into place. This steel-plate method is particularly effective 
where the pieces of the water jacket are cracked out in chipping the 

hole or crack, or when a single 
piece to be welded is broken 
into two or three pieces dur¬ 
ing the chipping. Another 
similar water jacket crack 
repair is that necessary when 
the forward cylinder water 
jacket containing the boss in 
which the steel fan shaft is 
screwed, becomes wholly or partly cracked or broken away. This is 
shown, and the repair partly indicated, in Fig. 35. The difficulty here 
is to make a repair which will withstand subsequent tendencies to crack, 
that is, to make the repaired part stronger than it was in the first place. 
This can be done as follows: Starting at the bottom of the crack, all 
work proceeds upward. A hole is first burned through, as at A. 
By starting here and working upward on the right side, the hole is 
gradually filled with new iron from a melt bar as indicated at 2. In 
all this work, excess iron is left both inside and outside. 

Having reached the top, the work starts again at the bottom and 
proceeds up the other side to the top. When this is reached, and the 
two welds joined, the job is completed. It has the appearance shown 
in the sectional plan at 3, with extra metal inside and out, all around 
the crack. In work of this kind, precaution must be taken not to 
melt or otherwise weaken the cylinder wall inside. 



Fig. 35. Process of Welding Cylinder Jacket 






























































GASOLINE AUTOMOBILES 


45 



Another cylinder weld frequently met is a flange cracked around 
a holding bolt. In such a break the fracture is usually confined to the 
flange, no part of the cylinder wall being broken or cracked. Thus, 
all the repair work is external, and proceeds more easily and quickly 
than would be the case when dealing with the more accurate cylinder 
wall. This is a simple repair, and is performed entirely from the 
outside by cutting the crack away on both sides to allow new metal 
to be added without increasing the thickness, then setting the piece 


Fig. 36. Method of Re-Assembling Piston Mechanism 


carefully in place, clamping it there and fusing new metal from a melt- 
bar into the V-slot formed by chipping. In case the crack does extend 
to the cylinder walls or bore, it is advisable to stop the weld about 
re inch from the interior surface of the bore. In this weld, as in 
previous ones, excess metal is left on the outside; in fact, this is done 
whenever and wherever possible, as the excess metal compensates 
for the somewhat brittle character of the weld and guards against a 
recurrence of the trouble by making the break stronger than it was 
in the first place. 





46 


GASOLINE AUTOMOBILES 


Working in Valve Cages. In overhead valve engines, when the 
valves are set in removable cages, it is often necessary to put in a new 
cage. This is worked in or seated in the cylinder by grinding it down 
to a perfect seat the same as a valve. Oil and emery are placed on 
the seat in the cylinder, the cage set in place and gradually worked 
around and down, until a perfect surface is obtained. The same is 
applied to renewing the seat when a valve cage shows signs of leakage. 

Replacing Pistons in Cylinders. When cylinders or pistons 
have been removed to be worked on, replacing these is a difficult job. 
There are two ways of doing this: viz, by a special form of ring closer, 
and by hand, using a string. The former is a shaped device which 

is clamped around the ring and squeezed 
together with pliers, using one hand, while 
with the other hand the ring is guided 
into the groove. The second and more 
usual method is illustrated in Fig. 36, and 
requires two men, unless the cylinder is 
of such a shape that it can be clamped 
in a vise. As the picture brings out, 
one man holds the cylinder while the 
other forces the piston carrying the rings 
into place. The piston is shoved in until 
the expanded top ring prevents further 
movement, when a heavy cord is placed 
around the spring, and the ends are 
crossed, thus closing up the ring and 
allowing the piston to slide in as far as the next ring. The operation 
is repeated successively for the other rings. This is a very simple 
method but it requires patience. 

When a block cylinder is to be replaced, this job is not so easy, 
for all the pistons, four or six as the case may be, must be lined up, 
and two of them entered at one time. This requires either special 
apparatus to help hold them or the services of several men. Most 
cylinders have a small bevelled edge at the bottom to facilitate this, 
but it is best to make a rig for a motor which is handled in sufficient 
numbers to warrant this. A handy form, and one easily made, is 
that shown in Fig. 37. This consists of a sheet-iron band of a depth 
equal to the total depth of the rings in the upper part of the cylinder 



Fig. 37. Simple Rig to Assist 
Pistons Entering Cylinder 
Casting 









































GASOLINE AUTOMOBILES 


47 


and is flanged over at the top to give it extra stiffness and prevent 
its entering the cylinder. It is made a little bit small for the size of 


the pistons over which it is to be used, so it will have to be sprung 
into place. \\ hen this is done, it will have a tight hold on the rings, 
compressing them so they will enter the cylinder. In applying it, 
care should be used to put it on squarely, and similarly in pushing it 
down by forcing the piston upward into the cylinder, as it should not 
be moved off of a ring until that ring has been entered in the cylinder 
enough so it is held therein. That is, the spring clamp should not be 
moved down below a ring until that ring is engaged and held within 



the cylinder. Its use is restricted to one size of motor, which is no 
hardship in a big shop where one make of car is handled exclusively. 
The small shop handling a variety of work would find half a 
dozen different sizes useful and 
economical. Moreover, the cost 
of this device is very small. 

A modification of the above 
device consists of a similar small- 
size band of sheet metal, made 
very wide, but without the upper 
flange. It is made, however, with 
a ppbr of right-angle lips where the 
two sides meet, these are drilled 
for a clamping bolt. This bolt 
has a wing nut with clamping rings to compress the lips. Another 
modification of the above is a loop or strap of narrow sheet metal 
having an additional loop to go over the two ends. These ends 
are made with a right-angle bend close to the piston-curve portion, 
and the compression of the rings is effected by pressing the sides of 
the clamp tightly against them, then sliding the small loop along the 
ends to hold this tightness. 

Rigging for Replacing Piston. In motors of the detachable-head 
type, like the Willys, the Chalmers, the Briscoe, and others, the 
work of replacing the pistons, particularly if the crankcase is 
cast integrally with the cylinder block, is considerable. In fact, it 
is sufficiently difficult to warrant making a special jig for guiding the 
pistons down into the long cylinder bores; this fastens onto the top 
of the cylinder where the head belongs. 


























48 


GASOLINE AUTOMOBILES 


As shown in the sketch, Fig. 38, the jig consists of a round shell, 
the interior of which is at the bottom of the same bore as the cyl¬ 
inder, but flares out considerably at the top. The base consists of 
the flange needed for turning this in the lathe and may be of any 
shape, size, and thickness. The action of the enlarged diameter at 
the top, gradually tapering to the exact cylinder size at the bottom, 
is to hold the piston rings in place and slowly contract them as the 
piston is lowered, so they pass down into the cylinder bore without 
trouble. One casting must be made for each cylinder bore, but the 
time and trouble which they save, and the injuries to workmen and 
parts which they avoid, make them well worth while. 

PISTONS AND ACCESSORIES 

Piston Construction. The pistons of automobile motors have long 
been made of cast iron, with the piston pin held in bosses on the piston 
walls. For all ordinary service this construction, well carried out, 
serves every purpose, but with the development of very high-speed 
motors, with piston speeds twice and three times as high as past 
practice has sanctioned, there is a growing tendency to substitute steel 
for cast iron in this important reciprocating element. 

Particularly in aviation motors has this been the case; the pistons 
of one well-known revolving motor, for example, are machined 
to the thinnest possible sections, out of a high-grade alloy steel. In 
this motor, the connecting rods are hinged to the head of the piston 
instead of to the walls, which can be made much thinner than other¬ 
wise would be possible. This practice has been followed to a slight 
extent by some automobile manufacturers. There are now a few 
stock cars of established quality provided with pressed-steel pistons. 

In cars, too, the movement toward smaller bores and higher 
efficiency has brought about the use of much lighter pistons; this 
is done by making them thinner and shorter. The latest develop¬ 
ment has been the use, not only of aluminum pistons and die-forged 
aluminum alloy connecting rods, but also of aluminum cylinders 
having cast-iron sleeves driven in to form the actual cylinder surfaces. 

Modern Tendencies. The modern tendency is to cut down the 
weight. This has been done by lightening the piston all over and 
by taking out rings. With fewer rings, it is necessary that each should 
be more efficient, consequently there has been much experimenting 


GASOLINE AUTOMOBILES 


49 


done with new forms. The lightening of piston weight has not 
materially changed the old open-end trunk form, although the use 
of aluminum has modified its straight shape somewhat in the hour¬ 
glass and similar forms. Attempts to utilize so-called free pistons, 


!' 



Fig. 39. Old and New Types of Pistons 
Former Heavy Piston at Left; Present Lighter Type at Right 

Courtesy of Locomobile Company of America, Bridgeport, Connecticut 


in which the upper part is flexibly connected to the lower, and the 
use of combinations of pressed steel and other metals have done 
much to modify the general form. 

Both these tendencies are well shown in the illustrations, Figs. 
39 and 40. The former shows how a certain piston was lightened by 
taking out two rings at the top, one rib inside, and generally using 
thinner metal. The old form is shown at the left, the new at the 
right. The other tendency is seen in Fig. 40 
which is an aluminum alloy. Note how this 
is cast to have less metal at the piston boss 
and also to be strong without extra ribs. 

Characteristics of Piston Rings. Cast 
iron for piston rings, long used to the exclu¬ 
sion of everything else, is in slight degree 
yielding its pre-eminence for this purpose 
also. This is because it has been found, in 
aviation motors with steel cylinders, that 
bronze affords greater durability and 
smoother running against the steel-cylinder 
wall, for which reason bronze rings—with steel or cast-iron springs, 
or “bull rings”, behind them—have been found most advantageous. 
Multiple rings, three or more in a groove, are finding favor. Their 
thinness necessitates the use of steel. 





•""m 




Fig. 40. Typical Piston Cast 
in Aluminum Alloy for 
Minimum Weight 

































50 


GASOLINE AUTOMOBILES 













Fig. 41. New Types of Piston Rings Designed to Retain Compression and to Increase 
Power, at the Same Time Reducing Wall Frictipn 

























































































GASOLINE AUTOMOBILES 


51 


Types of Piston Rings. Where formerly three or four plain rings 
were used, each one filling a groove, many pistons are now equipped 
with multiple rings of various patented forms, for which many 
advantages are claimed. Some idea of the variety of these may be 
obtained from Fig. 41 which shows a number of different forms. 

Thus, A indicates a ring with a double form, yet really it is ono 
continuous piece, cut so as to appear as two It is difficult to see any 
advantage in this, while it is much more expensive than the old- 
fashioned form. At B is seen a type which has an outer thin but 
high ring within an L-shaped inner form, both with plain vertical slots, 
and without holding pins of any kind. A somewhat similar form is 
seen at C, but with this difference, the inner ring has two steps 
instead of one, both have diagonal slots, and a pin keeps the outer one 
from turning. 

The form at D has a pair of thin and very flexible high rings, set 
one within the other. They are concentric, and both have stepped 
joints. The extreme flexibility would appear to take all the value out 
of their use as compared with the ordinary form. Another seen at E 
differs in that one part is placed above the other and held from rotat¬ 
ing by a pin. Both have diagonal joints. Both are eccentric and 
the pins hold them so the slots are 90 degrees apart. In the form at F, 
there are three pieces, including an inner one of full height with a deep 
outer slot, a modified U. The two outer parts are L-shaped and the 
L-projections fit into the slot of the big ring. All have diagonal slots 
and are pinned in place. 

An eccentric form, which has a tongue-and-groove arrangement at 
the open or thin end, is shown at G. The makers call this the lock 
joint. Practically the same effect is produced in the form shown at H, 
except that the opening is closed by a separate piece. This is called 
a guard, and it is machined to fit under one portion of the master ring 
and on either side of the slender ends, so that it makes up the full 
width. This use of the old-fashioned simple ring seems good. 

The form at I is that of B reversed, that is, the small square ring 
is placed on the inside of the L-shaped ring, and has, in addition, a 
horizontal step joint, while the outer member has a vertical step joint. 
An entirely different principle is utilized in the form at J, the inner 
L-shaped member having a taper, and the outer thin but high mem¬ 
ber having a corresponding taper to fit against it. The idea of the 


52 


GASOLINE AUTOMOBILES 


taper is that the spring of the two rings, slightly opposed, will work 
through this to hold both against the cylinder walls. The outside 
of the inner ring is knurled to hold the outer one from rotating. Both 
have diagonally cut slots. 

In the form shown at K, there are three parts, divided vertically, 
but in such a way that the top and bottom are really dependent upon 
the middle to hold them in place both vertically and horizontally. 
It is difficult to see greater merit in this form than of three plain rings. 
The form at L is somewhat like that at F, except that the inner full- 
height ring has a pair of projecting ridges in place of the single central 
slot. Each of the small half-width outer rings has a central slot, or 
groove, and end ridges to fit around this. Like F, this has the small 
outer rings pinned, but differing from it, all have diagonal slots. 

In the form seen at M, three parts are used, but the center full- 
height piece has its outer surface in the form of a double taper, upon 
each half of which one of the small half-height outer rings of triangular 
cross-section rests. In that shown at N, the ring is a continuous 
spiral, being somewhat similar to A in this respect. Its cut, however, 
is upon a slope all the way, so that its thickness varies continuously. 
It is made of heat-treated steel. It is difficult to see how the vertical 
spiral effect can make it tighter in a horizontal direction. 

Piston Pins. Piston, or wrist pins, as they are variously called, 
are usually very simple. In general, when the pin is a light drive 
fit or any easy fit in the piston, it is made from a high quality of car¬ 
bon steel tubing of considerable thickness, ground on the outside to 
size, and drilled for the locking pin (when one is used). It is then 
hardened and finish ground. In some instances it is simply a tight 
fit, with a ring fitted around the outside of the piston at its center, 
to form a lock. In other forms it is clamped in the connecting rod 
and turns in bushings in the two piston bosses. The general method, 
however, is the use of a hollow pin, the variation coming in the method 
of locking. Thus there is the use of two locking pins which project 
into holes; of two set screws which bear against grooves for this pur¬ 
pose; expansion plugs screwed into the split ends; spring plungers in 
holes in the piston; and of complex built-up pin sections with tapers 
bearing upon each other so as to be self-locking. The really important 
point is to have the pin so locked in place that it can never work out 
and score the cylinder walls, and yet be easy to disassemble. 


GASOLINE AUTOMOBILES 


53 


Piston and Ring Troubles and Repairs 

Removal and Replacement of Pistons. Speaking of pistons, 
there are several things that the beginner should learn about their 
removal and replacement. While it is not a difficult matter to pull 
a piston out of a cylinder, when both have been previously lubricated, 
and all proper precautions taken to loosen connecting parts, there 
are a few important things to remember. 

The piston should be drawn out as nearly parallel to the axis 
of the cylinder as is possible, accompanied by a twisting motion not 
unlike taking out a screw, in case it sticks a little. If the piston 



Fig. 42. Method of Removing Piston Rings 


sticks badly, pour in a little kerosene and work the piston in and out 
so as to distribute the kerosene between the two surfaces. 

To get at the spaces the rings must be removed, and as they 
are of cast iron and very brittle, this is a delicate task. Two 
methods of accomplishing this are illustrated in Fig. 42. If the 
owner has a pair of ring-expanding pliers, the rings can easily be 
expanded enough to lift them over the edge, as shown in (a). As 
very few owners possess this useful tool, however, a more common 
way is shown in ( b ). Secure a number of thin, flat steels about 




















































































































54 


GASOLINE AUTOMOBILES 


\ inch wide and ye inch thick—corset steels, flat springs, or hack-saw 
blades may be used, although the latter require more care on account 
of the teeth along one edge. The length of these steels should be 



Fig. 43. Tool for Moving Piston Rings Which Prevents Breakage 


such as to reach from about an inch below the last ring, to the top. 
Lift out one side of the ring with a small pointed tool and slip one 
of the steels between the ring and the piston, then move around 
about one-third of the way and insert another, taking care to hold 

the first in place; repeat the opera¬ 
tion with a third steel. When these 
are in place, the steels will hold the 
ring out from the piston far enough to 
be slid over the “lands” between the 
grooves and along the steels to the top. 

Always begin at the bottom and 
work up when removing rings, and 
just the opposite, from the top down, 
when replacing them. After one is 
mastered, the removal of the others 
is a simple matter of repetition. The 
grooves can now be scraped free of 
the offending carbon, a process which 
is but an inversion of the previous 
method. After this it will be neces¬ 
sary to replace the rings. 

A modification of the simple home-made ring spreader just shown 
is that depicted in Fig. 43. This is made with a stop, which prevents 
opening the pliers beyond a predetermined distance and thus 
prevents breaking a ring by continued pressing on a stiff or stuck 



Fig. 44. Simple Piston Ring Remover 





















GASOLINE AUTOMOBILES 


55 


one until it gives suddenly and is then spread beyond the resisting abil¬ 
ity of the iron. It is applicable to all forms of rings, except those with 
diagonal slots. In addition to the construction shown, it is desirable 
to fit a spring which will draw the handles together when not in use. 
This closes the jaws and keeps them closed, ready for immediate use. 

An even better and more simple form, but without the safety feat¬ 
ure of that just mentioned, consists of a large diameter steel spring, 
shaped not unlike a very big piston ring, which has a pair of handles 
fitted to the ends. This is shown in Fig. 44, which indicates how 
the nubs on the two handles are shaped so as to take hold of stepped 
joint rings. By making these nubs differently, any form of ring can 
be handled. A device of this sort saves the repair man lots of time. 

Loosening Seized Pistons. When the pistons and rings freeze 
into the cylinder, or seize because of a lack of lubricant, there is 
nothing quite so good nor quite so quick acting as kerosene. The 
cylinder head should be opened as quickly as possible, and the 
kerosene poured in liberally on top of the pistons. This should be 
done in each cylinder. Kerosene is thin and will work down between 
cylinder wall and piston rings, gradually cut¬ 
ting away the two where they have frozen 
together. If kerosene is not available, take 
che thinnest lubricant at hand; heat it so that 
it will be still thinner and more penetrating, 




Fig. 45. Simple Piston-Pin Pulling Outfit 


Fig. 46. Piston Ring Puller 
Which Allows for Exit of Pin 


then pour it in. At times, olive oil can be combined with kerosene 
to advantage. 

Freeing Wrist Pins and Bushings. When the piston pin or 
wrist pin is inserted directly in the piston it is usually a tight fit, 
so tight, sometimes, that the repair man experiences difficulty in 
getting it out. To overcome this difficulty, a piston pin puller is 















































56 


GASOLINE AUTOMOBILES 


needed. One of these, shown in Fig. 45, is made from a piece of steel, 
a steel strap, and a large cap screw. r I his piece of steel is drilled and 
tapped for the cap screw, and for the bolts to hold the steel strap. 
Then the latter is fastened so as to be about \ inch larger in diameter 
than the piston, or still larger if a long cap screw is available. When a 
pin is to be removed, the strap is put around the piston and the cap 
screw screwed in until it bears against the end of the pin. This can 
be done by hand. Then a wrench is applied, and as the screw is 
forced in, the pin is forced out on the opposite side. Be careful to see 
that the far side of the steel band is below the piston pin hole, so the 
pin will be able to come out without touching it. 

This can be simplified by having an endless steel band with a 
nut on the inside of it to form a backing for the cap screw to work 

against, or, the steel band can 



be welded to the nut. 

A form which removes 
the above difficulty is that 
shown In Fig. 46. This is 
made so that it holds around 
the piston at two points, 
above and below the piston 
pin, leaving room for the pin 
to come out. While more 
elaborate than the first one 
described, it is still very simple. For hollow piston pins, a different 
form of tip on the screw is needed, as the point, or tip, must press 
against the outer circular ring instead of against the center. This 
can be obviated, however, by laying a special round piece of metal 
over the end of the hollow pin before starting to apply pressure to 
force it out. 

Bushing Removers. When the piston pin is fixed in the con¬ 
necting rod and rotates in bushings in the piston bosses, it is some¬ 
times necessary to remove these bushings. A somewhat similar 
device will do this work, except that a shoulder or stop is needed to 
come up home against the side of the bushing, while the screw or 
threaded end must be small enough to pass through the hole in the 
bushing, and long enough to come out on the other side so a nut can 
be applied. One of these is shown in Fig. 47. The disadvantage of 


























































GASOLINE AUTOMOBILES 


57 


Wrist-Pin 


this type is that the nut shown on the right, which is operated to 
force the bushing out, must rest against the surface of the piston 
while being turned around. If a small U-bar be made to rest against 
the piston side, with a central drilled hole through which the threaded 
end passes, the nut will bear against the outside surface of this, so 
that even if the nut should scratch, no harm will be done to the piston. 
These pullers are used as substitutes for an arbor press, but this is 
desirable, as the use of the press is likely to distort the more or less 
delicate piston. With aluminum and the lighter weight cast-iron 
pistons, this is a thing which it is desirable to avoid. 

Some motors have the wrist pin locked in place by means of an 
expanding nut with a sunken square hole for turning. To start these, 
a wrench with a square projection or tit to fit this is needed. Such 
a wrench is used on certain lathe chucks, so one can always be bor¬ 
rowed in a machine shop or tool room. 

Mandrel for Turning Pins. Because of its being hollow in 
many cases, the wrist pin is difficult to handle when any work must 
be done upon it. For this 
purpose, a mandrel is needed. 

The method of constructing 
and using this is shown in 
Fig. 48. This consists of a 
shaft with a taper at one 
end and thread at the other, 
for a tapered nut. The wrist 
pin is slipped on the outer 
end, the taper nut put in 
place against it, and the 
backing nut put on behind that. Then these are screwed up until 
the two tapers hold the pin firmly, after which it may be placed in 
the lathe and work done upon it. 

Speeding Up Old Engines by Lightening Pistons, Etc. As 
will be pointed out later under "Cams”, one way to speed up an 
old engine is to replace the old camshaft and cams with new ones 
giving more modern timing. Another and a less expensive and 
troublesome way in which this can be done is by lightening the 
pistons and the reciprocating parts. This the repair man will surely 
be called upon to do, as the manufacturer probably would refuse. 





£—' Wrist-Pin 


Biihiiiii 

inis 

— Llin.m.Mfi 

"j:.k 




Fig. 48. Tapered Mandrel for Holding Hollow 
Piston Pin for Lathe Work 






























58 


GASOLINE AUTOMOBILES 



In order to get out any amount of metal worth the trouble, it 
will be necessary to drill from 12 to 20 or more holes of from ^-inch up 
to 1-inch diameter, depending upon the size of the piston as to bore 

and length. In a six-cylinder motor, 
this amounts to almost 100 holes 
(even more in some cases), and as 
these must be drilled with consid¬ 
erable similarity in the pistons, it is 
well worth while to construct a fix¬ 
ture to aid or speed up this work. 

One idea of the way such a 
lightened piston should look when 
finished is given in Fig. 49, which 
shows the steel pistons used in the 
Sunbeam racers. These are made 
this way to give the maximum of 
lightness with strength. Although 
made from steel, this is done 
simply to get very light side 
walls, and the general appear¬ 
ance of the skirt with its 
many drilled holes is just 
what the repair man should 
try to get when he starts to 
cut down the weight of stand¬ 
ard pistons for racing or speed 
purposes. 

Clamp for Pistons. The 
first requisite is a clamp, Fig. 
50, to keep the piston from 
turning, so that it will not 
break the drill. A good way 
to begin is to construct a base 
with a pair of uprights having 
deep 90-degree V’s in them; 
this is made so that it can be 
bolted to the drill-press table. The V’s should be lined with leather 
or fabric. Discarded clutch or brake linings answer this purpose 



Fig. 50. A Home-Made Wooden Stand to 
Facilitate Drilling Out Pistons 
















































































GASOLINE AUTOMOBILES 


59 


very well. To one of the uprights is pivoted a long handle, having 
a lined V which matches with that of the upright below it, and gives 
a good grip on the piston. 

Drilling Holes. When drilling to save weight, the holes are 
put in close together and in regular form, the idea being to take out 
as much weight of metal as is safe. In doing this, it is well to work 
out a scheme of drilling in advance, to make a heavy brown paper 
template, and fasten this to each piston in turn. It is not advisable 
to remove all the metal possible at first, but only enough to show the 
benefit of the method; after it has proved satisfactory, the first job 

may be improved upon later. For instance, in lightening pistons, 

♦ 

it is a good plan to use a f-inch drill the first time, and not to put in 
too many holes. If this proves satisfactory, and the owner comes 
back for more, you can go over the same lot of pistons, using a J-inch 
or f-inch drill between the existing holes, and thus reduce the weight 
of the lower end of the piston to its lowest possible point. 

Testing Size of New Piston. A skilled repair man gives the 
following suggestion relative to trying new pistons for clearance: 
When not certain whether the new piston will give sufficient clearance, 
heat it to about 600° F. If it is a snug fit in the cylinder, it probably 
will give satisfaction under normal running conditions. This, of 
course, is only approximate as the cylinder would heat up in use and 
expand but it serves the purpose and is quickly and easily done. 

Non=Leaking Rings. Another repair man says that when the 
rings get old, they can be made compression proof by grinding down 
so that two old ones will occupy the space formerly taken by one. 
This would work well for the top groove with a new ring lower down. 

Sometimes a ring will get broken when no others, either old or 
new, are obtainable. In such a case, the ring can be welded, if unusual 
care is exercised not to melt away any of the metal. 

When rings must be turned in the lathe, either for reducing the 
thickness or for truing up the face, a wooden face plate should be made 
with a slightly tapered groove for the ring to fit into. The ring 
should be pressed into the groove, and its natural spring will hold it in 
place. When working on the outer diameter, the face of the wood 
will have to be cut away sufficiently to allow the ring to project, or, 
instead of a single large central hole, an annular ring can be turned in 
the wooden face plate, the ring being fitted over the outside of it. 


60 


GASOLINE AUTOMOBILES 


Tracing a Ring Knock. Many times there is an elusive light 
knocking or chattering in the motor, especially at low speeds, which 
cannot be run down. This is often due to piston rings wearing at the 
top and bottom so they are loose in their grooves. When the piston 
moves upward, these rings remain stationary until they strike the 
bottoms of their grooves; when it moves downward, the rings strike 
the tops of the grooves. At low speeds, these noises can be distinctly 
heard; but at higher speeds, they are so faint that they blend off into 
the general murmur of the engine. Another noise, which comes from 
the rings, is that due to weakness or loss of spring. This is shown by 
a sharp rapping somewhat like a piston slap, when the throttle is 
opened suddenly. If the rings, and especially the top ring, are not 
stiff enough to resist the compression and explosion, this force will 

compress them. At the end of the stroke, 
they will expand suddenly against the 
cylinder wall, causing the rapping 
described. A notch filed in one edge so 
the pressure can leak in behind the ring 
will help matters, although new rings are 
better. 

Curing Excessive Lubrication. Holes 
in Pistons. When it comes to drilling 
holes to provide an outlet for the excess 
oil in the cylinders and so to reduce 
smoking, small holes, J-inch for example, 
are sufficient. They may be drilled in on any spiral plan by simply 
beginning near the bottom and working up close to the piston-pin 
bosses along a spiral track. The advantage of the spiral arrangement 
is that no hole is above another; the dripping from each hole is 
therefore distinct, and the quantity which runs down is greater. 

Grooving Pistons. Another method of curing the excessive 
lubrication to which the older cars—particularly those with splash 
lubrication—are subject, is to turn a deep groove in the bottom 
of the piston, about like a piston-ring groove but with the lower edge 
beveled off. When this is done, much as shown in Fig. 51, a series 
of small holes—made with a No. 30 drill—are put in at the angle of 
the bevel; 6 or 8 holes, equally distributed around the circumference, 
are probably enough. The sharp upper edge acts as a wiper and 



Fig. 51. Method of Grooving and 
Drilling Piston to Overcome Exces¬ 
sive Lubrication and Smoking 






















































































GASOLINE AUTOMOBILES 


61 


removes the oil from the cylinder walls into the groove, whence it 
passes through the holes to the piston interior and there drops back 
into the crankcase. No ring is placed in the slot as it would prevent 
the free passage of the oil. This device stops the smoking immediately. 

Loose Pistons. Many times the pistons will wear just enough so 
that they are loose in the cylinder all the way around. This causes 
leakage of gas, piston slaps, and other similar troubles. If the owner 
of the car does not care to buy new pistons, or if the car is an 
“orphan”, or if, for other reasons, pistons cannot be obtained, the 
clever repair man can remedy the trouble at small expense. The 
process consists in heating and expanding the old pistons. The 
heating is done in charcoal and must be done very carefully and 
slowly. After the pistons become red hot the fire is allowed to go out 
slowly, so that the piston is 
cooled in its charcoal bed. 

Sometimes as much as ToVo 
of an inch can be gained in 
this way. When the pistons 
are so far gone that they 
cannot be handled in this 

^ ay > they must be replaced Fig. 52. Rigging for Holding Piston against Face 
•ii _ Plate of Lathe 

with new ones. 

Mounting Pistons on Lathes. It is difficult to handle a piston 
in the lathe, or machine the outside in any manner, as a chuck does 
not get enough of a hold on it, and is likely to mark the surface. 
When work on it is necessary, the piston can be handled effectively 
by using a small rod with an eye at one end. This is made to fit the 
piston pin in the case of an old piston. The rod is run through the 
hollow spindle and bolted at the outer end. The tightening of the nut 
on it pulls the piston up against the face plate as Fig. 52 shows. 
This same method can be used when making a new piston. In the 
latter case, it is held in the chuck to finish the outside and inside, then 
the wrist-pin hole is drilled, bored, and reamed, and the wrist pin fitted. 
Finally, the finishing cut, or grinding of the outside, is completed. 

CONNECTING RODS 

Design Characteristics. H-Section Form. Established prac¬ 
tice in connecting-rod design is almost all in favor of the common 


Mead Stock-, 






























62 


GASOLINE AUTOMOBILES 



H-section rod, usually with two bolts to attach the cap. In some 
cases four bolts are used, since with four bolts a flaw or crack in one 
is less likely to cause damage than is the case when only two are used. 
The old scheme of hinging the cap at one side is now practically 
obsolete, having been discarded because it made accurate adjustment 
of the bearing surfaces almost impossible. 

Tendency to Lighten Rods. The modern tendency toward 
lightening the weight has extended to the connecting rods, since a 
portion of the rod is considered as reciprocating. This lightening 

has been accomplished by 
external machining. Thus, 
in the typical connecting rod 
of forged alloy steel, shown in 
Fig. 53, the form at the left is 
that formerly used, while that 
at the right is its present 
shape. Note how the round¬ 
ing sides of the H-part, nec¬ 
essary in forging, have been 
machined off; how the fillets 
at big end and piston end 
have been machined down; 
how the upper end has also 
had its central rounding part 
machined off; and the whole, 
file finished. Another excel¬ 
lent feature of the work done 
to lighten the rods in this 
way is that they can be 
brought to an absolute stand¬ 
ard of weight, so that every 
rod weighs exactly the same as every other. This was not pos¬ 
sible previously, as the variation of the exterior surfaces, due to 
differences in forging, made considerable difference in weight. In 
both, the bushings are in place. 

Tubular Rods. Tubular rods, in place of the H-section, are 
giving good service in several of the long-stroke foreign motors, and 
it is difficult to see why this form is not superior to that in common use« 


WB2 


.. 


Fig. 53. Old and New Connecting Rods Showing How 
They Can Be Lightened 

Courtesy of the Locomobile Company of America, 
Bridgeport, Connecticut 












GASOLINE AUTOMOBILES 


63 



The question of cost, however, is a consideration, since it is necessary 
to bore the hole through the inside of the rod, whereas a forged rod 
cf H-section requires no machining except at the end. 

The wonderful progress in welding, however, has made it possible 
to construct a tubular connecting rod at a very low expense, and, owing 
to its many advantages, this is finding much favor for small motors. 
The two ends are machined and a section of tubing welded to them. 

One advantage of the tubular rod, in addition to its superiority 
for withstanding the compression load to which a rod is chiefly sub¬ 


ject, is that it can be used as a pipe to convey oil from the big end 
to the piston-pin bearing. 

Fig. 54 shows an example of a very light-weight, high-quality, 
aviation-motor connecting rod, machined out of a solid bar of 
alloy steel, and provided with four bolts in the cap. 

Connecting=Rod Bearings. Usual Types. Connecting rods have 
two different forms of bearings. This is due to the difference in their 
service. At the upper or piston end, the bearing is usually a high- 
grade bronze tubing, machined all over and pressed in place. When 
in place, it generally has a central oil hole drilled through rod and 
bushing, and then a couple of oil grooves are scraped in by hand to 
start from this hole and distribute the oil outward in both directions 
on its inner surface. 


Fig. 54. 


Connecting Rod Machined Out of One Piece of Alloy Steel, 
with Four Cap Bolts 





64 


GASOLINE AUTOMOBILES 



At the lower or, as it is usually called, big end, the connecting rod 
must have a better bearing. This end is bolted around the crankshaft 
pin and must sustain high rubbing speed, as well as the load of explo¬ 
sions. Bolting it on, and the need for removing it occasionally, call 
for a form which is split horizontally. Generally, this bearing is of 
high-grade bronze with a softer, or babbitt, central lining which can 
be replaced easily and quickly. The harder bronze back will sustain 


Fig. 55. Connecting Rods for V-Type Engine, Showing Method of Forking One Rod 
Courtesy of Cadillac Motor Car Company, Detroit, Michigan 

the stresses of bolting up tight and stand up under the constant 
pounding, while the softer and renewable center takes all ordinary 
wear. These bearings are fitted with great care. They are reamed 
by hand after machining, and then hand scraped to a precise fit. 
They are pinned in place, drilled for oil, and grooved to distribute it. 

Eight- and Twelve-]'-Types. The eight- and twelve-cylinder 
V-type motors have altered the design of connecting-rod bearings 










GASOLINE AUTOMOBILES 


65 


somewhat, in that there are two connecting-rod big ends working 
upon one crank pin, that is, an eight-cylinder V-engine uses a four- 
cylinder form of crankshaft with two connecting rods on each pin. 
This modifies what was good connecting rod bearing practice, one of 
two different forms being utilized. When the rods are placed side by 
side with individual bearings, the pins are made very large and as long 
as possible, in order to give adequate bearing surface. The other 
form is the forked rod in which one rod works within a slot in the 
other. In this type, a split bearing of the usual form is placed in the 
forked or long rod, and the outer surface of the central part of this 
prepared as a pin surface for the other or central rod. The requisite 
area of the smaller rod bearing is made up by its larger diameter. 
This is well shown in Fig. 55, where the rods and bearing are shown 
assembled, and the separate big-end bearing is shown at the right. 
In another type of V-motor connecting-rod bearing, the larger bearing 
is slotted for the central rod and its bearing, the slot being made large 
enough to permit a rotation, which never exceeds a quarter of a turn. 
This arrangement is more complicated to install and repair than the 
form shown. 


Connecting Rod Troubles and Repairs 


Classification of Troubles. In general, all connecting-rod 
troubles come under one of four headings: straight rod, proper bear¬ 
ing adjustment, mechanical work (scraping bearings, straightening rod, 
or other work), and special equipment for doing connecting-rod work. 


Straightening Bent Rod. The need for a straight and true 
rod is apparent, but it is surprising how many rods are not straight, 
particularly in old motors. 

Many erratic and bad- 
sounding motors, have all 
their trouble caused by a 
bent rod. A connecting 
rod can be bent either of 
two ways, and one gives as much trouble as the other. If bent in 
the plane of rotation, the rod will simply be shortened, the piston will 
not go as high as it should, and it will go down a little lower than 
normal. Moreover, the bend will press it with unusual force on the 
cylinder v ail on one side and cause it to wear moie than the other. 



Fig. 56. 


Method of Testing Connecting Rods 
with Two Mandrels 



















'66 


GASOLINE AUTOMOBILES 


The combination will soon result in trouble. When bent in a longi¬ 
tudinal direction, that is, fore and aft, the upper end of the rod will 
run against one side of the piston or perhaps only knock against it 
on each stroke. At any rate, this too, will give trouble. 

Methods of Testing Straightness of Rods. The first thing to do 
when a connecting rod is suspected is to take it out and test it. One 
way of doing this is to attach the lower end to a mandrel, which 
can be bolted into a drill-press table, as shown in Fig. 56. Before 
doing this, the small end is also fitted with a mandrel, the lower part 
of which is of considerable length and has two short vertical pegs. 
When the big end is bolted down, if both the small pegs on the other 
end touch, it proves at least that the two holes (big end and small 
end) are parallel. If one of these pegs is off the table as shown, 



it proves that the two holes are not parallel. In the latter case, the 
rod would need to be straightened, as nothing but the bending of the 
rod would throw the holes out of parallel when they were bored 
correctly. 

Another method, which is very similar, consists in forcing two 
mandrels of equal length into the two holes, until each is centered in 
the rod. Then, if the rod be placed on supports on the surface plate, 
or other similar true surface, so that one mandrel is horizontal, the 
surface gage will show at once if the other end is also horizontal, 
and thus, if the rod is straight and true. It will also show how much 
it is twisted, if out of true. If the mandrels are made long enough, 
ordinary calipers can be substituted for the surface gage with equally 
accurate results. 

A method almost the same as that just described is utilized in 
the testing fixture shown in Fig. 57. The advantage of such a fixture 













































GASOLINE AUTOMOBILES 


67 



Fig. 58. Connecting-Rod Straightener Constructed 
from Three-Quarter-Inch Bar Stock 


is that it always works the same, while the use of surface gages 
and calipers varies from one workman to another, and even with the 
same man, from day to day, according to his moods and feelings. 
As the sketch shows, there is a mandrel for each end of the rod, that 
for the big end being pivoted in the fixture. When the rod is forced 
into this, and the other 
mandrel put in place in the 
piston end, if rotated down 
to a flat position (as shown), 
the small end mandrel 
should touch both of the 
fixture stops. If badly 
twisted, it will not be able 
to go down on one side. 

S'tr(lightening Jigs. 

When it has been proved 
that the rod is not straight, it is necessary to have a device for apply¬ 
ing pressure in order to straighten it. The simplest way is an ordinary 
straightening press consisting of a pair of ways with V-blocks upon 
which the work is supported and a lever or screw to apply the pressure 
in the middle. The work is supported on the V-blocks, the distance 
apart varying with the amount it is to be bent—far apart for a 
big bend, close together 
for a small one. For as 
short a member as a con¬ 
necting rod, however, 
this is not sufficiently 
accurate, and besides, the 
form of the rod does not 
suit it to good results by 
this method. 

A simple fixture for 
bending a rod, shown in 
Fig. 58, consists of a pair of hooks for holding it and a central 
screw for applying power. The rod is slid into place inside the 
hooks and the screw turned until the rod is straightened. Then to 
prevent its springing back when the pressure is released, it is peened 
on the side opposite the screw. The advantage of this method is 



Fig. 59. Box Type of Connecting-Rod Straightener 









































GASOLINE AUTOMOBILES 


1)8 


that it throws all stresses upon the rod itself and none on the bear¬ 
ing surfaces. The hooks are forged from high-carbon steel of f-inch 

square section. The screw should be not 
less than f inch to f inch in diameter and 
fine threaded. 

Another fixture is on the box order, 
shown in Fig. 59. This has a pair of end 
clips which hold the rod tight by means of 
wedges which are driven into place. When 
this has been done, the rod is straightened 
by means of the central screw. As will be 
noted, the principal difference between the 
two forms, Figs. 58 and 59, is in the holding 
method. There are other forms, as well as 
forms of mandrels for lapping in big-end 
bearings, which are so constructed as to give 
a check on straightness and to allow of 
remedying the situation if the rod is not 
straight. Some of these will be described. 

Offsetting Causes Trouble. Many motors 
are built with offset connecting rods, that 
is, the application of pressure on the upper 
end is not upon the center line of the bottom end. This is exaggerated 
in Fig. 60, which indicates also how this situation causes wear on 

the upper left end and lower right 


end of both bearings. The sketch 
also shows how this unequal wear 
is greater on the crank end, which 
is offset, than upon the piston 
end. The cause of this wear is 
simple, the pressure is unbalanced 
on the left side, so a downward 
push on that side is taken up by 
extra wear there, and on an 
upward push, as on the compres¬ 
sion stroke when the flywheel is 
driving the pistons, the extra resistance of the left side causes unusual 
upward pressure on the right side. So the ends continue to wear, until 



Fig 


60. Offset Connecting 
Rod Showing How Bear¬ 
ings Wear 



Fig. 61. Wooden Core for Babbitting 
Connecting-Rod Bearings 





























































































GASOLINE AUTOMOBILES 


69 


a rocking motion of the pins results, and this causes a noise. New 
bearings help temporarily, but a stiffer connecting rod will often 
remedy it more or less permanently. 

Adjustment of Connecting=Rod Bearings. Babbitting Bearings. 
As has been stated, the majority of connecting-rod and crankshaft 
bearings are bronze shells or backs, lined or faced with babbitt as a 
wearing metal. The bronze provides the stiffness and long life, the 
babbitt, the softer wearing face which is easily and cheaply replaced. 
In this replacement, a form or jig to simulate the crankpin and 
approximate its size must be used for a center. A form made of 
wood is shown in Fig. 61. This is simply a round member of hard 
wood, turned up slightly smaller than the actual crankpin at the 
upper end, while the lower end is left large to form an under surface 
for the metal. Next, the upper part is split or rather has a cut taken 
across it, equal in thickness to the shim to be used when the bearing is 



assembled in place. Then, when the babbitt is poured in, a metal 
member is set across the rod to form the shim, which is shown in the 
smaller sketch at the right. 

This method has the advantage over that of using the pin when 
pouring the metal in position, because it gives a little surplus to 
machine off, and thus makes the surface more accurate before it is 
scraped. If broaching to harden the surface of the metal is resorted 
to, it gives a little metal to broach down. Moreover, by making it 
so simple and easy to handle, the work of babbitting is made easy. 
This cannot be said of trying to babbitt in place. The core need not 
necessarily be of wood; it can be of metal or of anything else desired. 
But the wood has the advantage of being easily worked, or oftbeing 
cheap and quickly obtained. 

Kinks in Adjusting Bearings. Usually, crankshaft and connect¬ 
ing-rod bearing adjustment is a difficult job. This is particularly 


























70 


GASOLINE AUTOMOBILES 


true when the engine is not removed from the chassis. The con¬ 
necting-rod bolts are tight and hard to reach, and the operator, who 
is lying on his back, has all dislodged dirt or oil dropping in his face. 
Work like this calls for an easy means of getting under the engine and 
out again. For this, a form of creeper is necessary. There are many 
forms made and sold, but a simple one which any repair man can 
construct for himself is shown in Fig. 62. This consists of a wood 
frame with casters at the four corners and longitudinal slats for the 
floor. By making the ends concave, the surface is made concave. 
With a pillow or other head rest, it is more comfortable to use. 

Another way in which this work may be facilitated is to make a 
special socket wrench for connecting-rod nuts and to make it deep 

enough to hold four nuts, one 
over the other. Then with a 
spring-stop arrangement, Fig. 63, 
the nuts from two rods can be 
taken off without stopping; or if 
lock nuts are used, the nuts and 
lock nuts may be removed from 
one rod. This is accomplished 
by means of four spring-operated 
pins. When the first nut is 
removed, it sticks in the end of 
the tool, but pushing this into the 
second one moves the first nut on 
up inside the socket. In replace¬ 
ment, when the upper pins are pulled, a nut drops down and is held 
by the lower pins enough to start it on the bolt end. When tightened, 
the socket can be pulled off, and the next nut dropped down and fixed 
in place by hand. The four pins have hardened ends, and the springs 
are old clock springs to which the upper pair of pins are brazed. 
The lower pins can be free. Tliis form of socket wrench can be used 
with equal advantage in many other inaccessible places. Its single 
drawback is that it can only be of one size; and a set of them have 
to be constructed to take care of all needs. 

In ordinary bearing adjustment, the nuts are taken off, the 
connecting-rod cap removed, and the shims taken out; say, a shim 
of .001-inch thickness for very small wear, .002 inch for considerable 

























































































GASOLINE AUTOMOBILES 


71 


wear, and .003 inch for severe wear. If more than this has been 
worn off the bearings, they need re-scraping, as this is about the 
maximum that can be taken out without scraping. Usually, when 



Fig. 64. Connecting Rod and Main Bearings Constructed without Shims 
Courtesy of Reo Motor Car Company, Lansing, Michigan 


the bearings have been taken up in this way, the caps are put back 
on pretty tight, a little bit tighter than they were previously. Then 
they are flooded with oil and run in this condition. The combina¬ 


tion of excess oil and tight 
caps soon gives the entire bear¬ 
ing surface a fine polish which 
will last for many miles. 

Special Sleeve Replaces 
Shims. In one motor (Reo), 
the shim is replaced by an 
ingenious arrangement of a 
threaded sleeve around the 
bearing bolts. This is shown 
in Fig. 64 in which the sleeves 
are marked A and the bolts 
B. It will be noted that the 



sleeves rest against the upper part of the bearing and have a head 
against which the bolts rest, so that the latter can be tightened only 
as far as the sleeves allow. With this construction, when it is desired 
to tighten a bearing, the socket wrench is slid on so as to hold the 
heads of both bolt and sleeve, and then turned to unscrew both. 





































































































































































GASOLINE AUTOMOBILES 


72 

Then the socket is drawn off the sleeve head, in the position shown 
at the left, and the bolt screwed back to pinch the bearing together 
and lock it. As will be noted, the two halves of the bearing metal 
are separated a considerable distance so that this arrangement is 
good for many thousand miles. Two years’ running will usually 
exhaust the possibilities of the original bearing and its shims, which 
calls for re-babbitting, re-scraping, new shims, or for an entirely new 
bearing. This form of construction could be used anywhere that 
the bearings are likely to need frequent readjustment. 

Mandrel for Lapping. In order to give the connecting-rod 
bearings the best possible surface, a mandrel should be used to lap 
them in. This is the equivalent of running in. The rod, with bear¬ 
ings in place, is put on the mandrel, and the bolts tightened a little; 
then it is worked back and forth, until the flattening down of the 
surface will allow more tightening of the bolts. This is continued 
until, with a mandrel the exact size of the crankpins, the bolts can 
be pulled up dead tight. Then the rod is removed; it is finished. 
Such a mandrel, shown in Fig. 65, is usually a piece of steel turned up 
on one end to the exact size of the crankpin, with a flat spot machined 
in the other end to allow holding in the vice. By making it perfectly 
straight, a try square against the mandrel will show the correctness 
of the rod. On the other hand, if the outer end be made with a very 
slight taper, it is easier to work the rod on and off and easier to 
inspect the inside surface without unbolting. 

Drilling Thin Shims. When thin brass shims are used, and the 
shape is formed by the workman, it is difficult to get a good true hole 
because of the extreme thinness of the metal. By collecting a num¬ 
ber of these together and clamping them between two blocks of 
wood, a straight true hole can be bored through wood and brass with 
an ordinary bit and brace. The use of laminated shims avoids all 
this, as they come in the required thickness and are drilled to size. 
With these, adjustment is simply a matter of peeling off one of the 
laminations. 

CRANKSHAFTS 

Material. The crankshaft in all but heavy slow-running motors 
should be made of the finest alloy steel obtainable, for it carries the 
practical equivalent of thousands upon thousands of heavy blows. 



\ 


GASOLINE AUTOMOBILES 


73 


Variation of Design. The 

greatest variations in auto¬ 
mobile crankshaft design, aside 
from those permitted or made 
necessary by differences in the 
quality of material, are due 
to the conditions involved in 
the different combinations of 
cylinders that can be utilized. . 
Thus the number of crank 
throws, as well as their posi¬ 
tion, varies with the type of 
motor. 

As the repair man knows 
crankshafts today, they are of 
two kinds. The first is the 
four-cylinder form, in which 
all throws are in a single plane. 
This type of shaft has four 
pins, one for each connecting- 
rod big-end bearing. It may 
have either three bearings, as 
shown in Fig. 66, or five bear¬ 
ings. The second type, which 
the repair man is likely to 
meet, is the six-cylinder shaft, 
which will have six pins for 
connecting rods; these are 
grouped in pairs, and each pair 
in a different plane, the angle 
between them being 120 de¬ 
grees. This type of shaft may 
have either four or seven bear¬ 
ings. In the four-bearing 
form, there is a bearing at each 
end, and another between each 
pair of cylinders, as shown in 
Fig. 67, with pistons and con- 



Fig. 66. Four-Cylinder Three-Bearing Balanced Crankshaft 
Courtesy of F. B Stearns Company, Cleveland, Ohio 
































































































































74 


GASOLINE AUTOMOBILES 




necting rods attached. In the seven-bearing form, there is a bearing 
on each side of each connecting rod. These are the modern types, 
but older shafts may be encountered occasionally, in the way of 
four-cylinder shafts with two bearings, one at each end only; also with 


Fig. 67. Six-Cylinder Four-Bearing Crankshaft with Pistons and Connecting Rods Assembled 
Courtesy of Nordyke & Mormon Company, Indianapolis, Indiana 

four bearings, the latter having the usual center bearing eliminated. 
The modern tendency is toward simplification, compactness, and low¬ 
ered first cost; and the shafts with the fewer number of bearings are 
on the increase. 


Fig. 68. Typical Drop-Forged-Balanced Crankshaft 
Courtesy of Park Drop Forge Company, Cleveland, Ohio 

Crankshafts may be found which are drilled out for lubricant pas¬ 
sages. In such cases, the repair man must look for attachments which 
feed the oil into the hollow interior. Also, he may meet a ball¬ 
bearing form of shaft which has been built up to allow the bearings 
to be assembled. Such a shaft should be handled with extreme care. 






GASOLINE AUTOMOBILES 


75 


Eight-cylinder engines generally use a four-cylinder form of shaft, 
with two connecting rods on each of the four pins. This is explained 
previously under connecting rods. Similarly, twelve-cylinder motors 
have a typical six-cylinder crankshaft, with two rods on each of the 
six pins. 

Balanced Crankshafts. While not an assembled shaft in the 
sense just referred to, the balanced form is meeting with great favor, 
and is being widely adopted. This will be met by the repair man 
in two forms. One is like Fig. 66, except that the weights are 
machined to fit on the crank cheeks and bolted there. The repair 
man should not remove these unless it is absolutely necessary, as 
they vary in size and weight. They are fitted in place with extreme 
care and fastened extremely well. The other type—the kind being 
introduced into the latest models—has its counterweights forged as a 
part of the crankshaft, Fig. 68. In this type, the weights are adjusted 
to make the proper balance when the shaft is being machined. 

Crankshaft Bearings. The bearings of the crankshaft in the 
crankcase do not differ materially from the connecting-rod bearings 
just shown and described. They may be a little longer, but the type 
is the same. They are pinned or otherwise fastened in the crankcase so 

as not to rotate, while the connecting-rod bearings are fastened in the 

/ 

connecting rods so as to rotate with them. A few shafts will be met 
which have ball or roller bearings, but the great majority have the split 
bronze-backed, babbitt-faced bearing described for connecting rods. 

Crankshaft and Connecting=Rod Bearing Shims. Practically all 
split or two-piece bearings for either crankshafts or connecting rods 
are assembled in place with shims. These are very thin flat pieces 
of metal set between the two halves of the bearing when it is 
assembled new to spread it apart. The shaft bearings are scraped to 
an exact fit on the pins with these shims or expanders in place. Then 
when wear occurs in the bearing, so that its inside diameter is enlarged, 
the bolts may be taken out, a shim or shims of the required thickness 
removed, and the bolts put back and tightened. This removal 
reduces the diameter of the inside of the bearing. To facilitate this 
action, the shims are generally put in, in such a way as to allow taking 
out a number of thousandths of an inch, there being two shims of 
two, two or more of two, possibly one of two, and a thicker one, or 
more of the very thin ones. These shims enable the taking-up of wear 



76 GASOLINE AUTOMOBILES 

amounting to toVo of an inch, when one of the thinnest shims is 
removed; i o Vo bv removing one of that thickness; two by removing 
a row and a two ; row by taking two 2’s, etc. 

Of course, a crankshaft bearing or a connecting rod-bearing will 
not wear entirely round, but the work of adjusting either bearing is 
reduced to a minimum bv the use of shims. When the wear is very 
bad, the bearings should be re-fitted and the shims left out. 

An entirely new form is the laminated shim. The total thickness 
required is built up of very thin laminations, either bne or two 
thousandths of an inch thick, so that in adjusting a bearing as many 
laminations are peeled off as are necessary to take up the wear, then 
the original shim, slightly lessened in thickness is replaced. 

In Fig. 66, the end view shows .both connecting-rod and crank¬ 
shaft bearing shims in place, and indicates how they perform their 
function of holding the halves of the bearing apart when the bearing 
is being fitted. 

Crankshaft and Bearing Troubles, and Remedies 

Bearings. Bearings of the two-piece, or split, type give the 
auto repair man fully as much trouble as anything, in fact, the 
crankshaft bearings should not be tackled until considerable repair 
experience has been had. In general, wear on the bearings is due 
to one of two causes: either to a soft metal which has caused vertical 
wear on the inside or outside of the lower half of the bushing, or to a 
vibrating shaft which has worn an oval hole somewhere in the length 
of the shaft, as at the inner or outer end. 

In the former case, the height of the worn half must be reduced. 
This is usually done by taking as much metal from the upper face as 
is necessary. When this has been done—either by filing or by 
rubbing across emery cloth wet with oil—the two halves of the bushing 
will approach so close together that the hole will be smaller than the 
shaft. This will necessitate scraping out, or reboring, according to the 
amount which has been taken off. In the case of very small amounts, 
this wear can be taken up by removing shims, as mentioned above. 

When the second form of wear is found, that is, when the bush¬ 
ing is worn oval by a wobbling shaft end, the only remedy is to bring 
the bearing halves together as before and re-bore. It may be that 
this operation robs the bearing plates of so much metal that they 





GASOLINE AUTOMOBILES 


77 


will not fit the holes in the case; or 
possibly the wear may have com¬ 
municated itself to the case, so 
that the hole there is out of true. 
If this be slight, refilling the cases 
with babbitt metal or building-up 
may be resorted to, but if the wear 
is considerable, a new set of bear¬ 
ings is the only remedy. In build¬ 
ing up the bearing, strips of soft 
metal are placed in the worn spots, 
after cutting or filing them to fit 
as closely as possible, and the bear¬ 
ing driven down upon them as firmly 
as possible. In this way, it is often 
possible to build up a worn crank¬ 
case to answer for many thousand 
more miles running. 

Bearing Wear. In this connec- 


between the crankshaft bearing and 
the pin, there is a space of perhaps 
.002 inch divided into .001 inch all 
around, and this space is occupied 
by a film of lubricant. So long as 
this is the case, if the metal remains 
hard and does not give under the 
constant pounding, and the film of 
lubricant stays unbroken, it remains 
a perfect bearing. But the film does 
get broken or reduced, and the softer 
metal does give, so we have a con¬ 
dition shown at A, Fig. 69. Instead 
of a cylindrical pin centered in a 
cylindrical hole, one or the other is 
worn oval. This is usually the 
bearing, for the weight of the 




tion, it is important to know how 




and why bearings wear. Normally, 



I 




Fig. 69. Wear in Crankshaft Bearings. A —Section through Worn Bearings; B —Flat Spot on Shaft; C —Incorrectly Fitted Shim; D —Bearing at C Fitted 

by Scraping Bearing and Case; E —Bearing at C Fitted by Scraping Shim only 






















78 


GASOLINE AUTOMOBILES 


shaft, coupled with the pressure on it, keeps it at the bottom of 
the hole. The tendency, then, is to increase this eccentricity. 
In this condition, the pin is running against the bearing metal at 
only one very limited surface, so all the pressure and all the wear are 
concentrated there. If the bearing is hard, or if a hard spot develops, 
the pin is likely to wear flat on the bottom side, as shown at B. When 
the bearing is fitted to the case, great care and accuracy are required. 
If care is not taken, an incorrect fitting, shown at C, results. Here 
the shim does not entirely fill the opening for it, and the bearing metal 
rests on the case at one point; on the shim at another; and does not 
touch either at a third. This is remedied by scraping both bearing 
and case, as shown at D, or the shim alone as seen at E. In the former 
it will be noted how the full shim has raised the bearing so that its 

points project into the pin, 
where scraping will be needed. 
In the latter case, also, scrap¬ 
ing the bottom of the bearing 
will be necessary, for using a 
fully fitted shim has raised the 
center more than the sides. 

Crankshaft Pounding. 
When the dull throbbing noise 
is found to come from within 
the crankcase, possibly be¬ 
tween two of the bearings, 
this indicates a crankshaft or a connecting-rod pound. That is 
to say, either the rod is loose on the shaft or the shaft is loose in one 
of its bearings. Whenever the force of an explosion comes on the 
piston and drives it down, this looseness is taken up quickly, and the 
dull pounding noise is made. This is a serious trouble and, if long 
continued, may wreck the engine. That is, the loose rod may become 
entirely loose and free so as to thrash around and, in so doing, wreck 
the crankcase; or, if the pound comes from the shaft, the bearing 
may continue to loosen and finally that part of the shaft become 
entirely free to thrash around. Both these troubles can be overcome 
by tightening of the bearing caps. 

Test for Tightness. When a connecting rod has been fitted to 
a crankpin and is ready for use, a simple test of correct tightness is 



Fig. 70. 


Holding Fixture for Crankshaft 
Bearing Caps 









GASOLINE AUTOMOBILES 


79 


this: If the rod is placed vertical, it will stay there, but if pulled 
over past 20 degrees from a vertical, it will swing down, of itself, 
to the bottom position and stop there 
without continuing to swing. If it 
will do this, it is just tight enough. If 
it will not swing down at all or con¬ 
tinues swinging, it is either too tight 
or too loose. To a certain extent, 
crankshaft bearings are delicate, and 
they can be ruined by having the 
big ends too tight. 

Holder for Bearing Cays. When 
a number of bearing caps have to be 
scraped, or filed down, it is worth 
while to make a holder for them. A 
plain form is shown in Fig. 70. This 
consists of a semicircular piece of 
metal which fits into the hollow part 
of the bearing, with each end pivoted 
on two L-shaped members. The mem¬ 
bers are held tightly in the vise, and the tighter they are gripped the 
tighter the bearing cap is held. This jig holds the cap with the desired 



Fig. 71. 


Semi-Socket Wrench for Crank- 
shaft Bearing Nuts 



Fig. 72. Set-Up for Supporting Crankshafts Out of Motor 

firmness, yet it leaves the whole upper surface free and clear so the 
workman can work at it readily and do a neat quick job of filing. 
































































80 


GASOLINE AUTOMOBILES 



The same layout is suitable for connecting-rod caps, except where they 
have an oil scoop or other central projection which interferes. 

Another Handy Wrench. The form of the crankshaft-bearing 
cap and also of the connecting-rod bearing cap are such that no space 
is wasted. Very often the nut is so close to the cap that it is difficult 
to turn, unless the cap is taken out of the motor where the wrench can 
be applied at right angles. The use of the socket form of wrench, 


Fig. 73. Dogs for Use in Turning Four-Cylinder Crankshafts 

however, does not make it necessary to take the cap out of the motor. 
Aside from the socket wrench it is hard to get any other form of 
wrench to use on these nuts that is not so small and thin that it 
has no particular strength. In Fig. 71, however, a form is shown 
which has all the strength of the very stiffest forms, and yet it can be 
applied to these inaccessible nuts with ease. Moreover, its con¬ 
struction is such that it can be applied and used readily. It consists, 
. as the sketch shows, of a solid socket wrench, as distinguished from 





GASOLINE AUTOMOBILES 


81 


the form made of tubing, and has part of one side of the socket cut 
away. This makes its quick application to the nuts easy,, although 
it also limits the amount of turn possible. Generally the case nuts 
are different in size from the connecting-rod nuts; so it is advisable to 
make the wrench double ende<. with a size at one end for the rods, 
and one at the other end for the case. 

Holding the Crankshaft. When the shaft has been removed from 
the engine, and work is to be done upon it, it is an awkward thing to 
handle. It is just delicate enough so that it cannot be handled care¬ 
lessly, yet its size and weight make it difficult to move around. 
Thus, in lapping the shaft pins, in fitting connecting-rod bearings, or 
doing other work upon it, a sup¬ 
port which is simple, easily moved 
around, yet adequate, is needed. 

Ordinarily a shaft is clamped in a 
vise, but this is not always satis¬ 
factory when working on an end 
bearing. The method shown in 
Eig. 72 has many advantages. 

This consists of a special bench 
fixture and a notched board. The 
latter should be at least 1-inch 
stock, that is, it should be f-inch 
when dressed on both sides. The 
former is simply a metal angle with 
a series of radial slots to take the 
flywheel bolts, with a central hole 
for the shaft to rest in. The metal above the hole is well cut 
away to facilitate putting the shaft in and taking it out. 

Handling Shaft in Machines. When the crankshaft is to be 
machined, no matter what the form of lathe, grinder, or other machine, 
the fact that the pins are eccentric necessitates a special dog or jig 
for holding it. If an ordinary flange is bolted on the end, the main 
pins can be turned, smoothed down, or ground, but the crankpins. 
cannot. What these latter need is a form of flange or plate with two 
exact centers on either Jde of the central one at distances exactly 
equal to the crank throw. One is shown in Fig. 73, which is attached 
to a four-cylinder shaft all ready for the machine. Above will be 



Tail~5tock 
- Center 


Fig. 74. Fixture and Lathe Jig for Turning 
Six-Cylinder Crankshafts 































82 


GASOLINE AUTOMOBILES 


seen another shaft without machining flanges. The bolts which 
attach the flanges to the shaft can be seen beyond the right-hand 
flange and at the far end. The rack in the background, on which 
these shafts are placed, is of interest also, forming, as it does, a simple 
and efficient means of holding the shafts, yet it is convertible for 
holding other parts or units. It is simply a stout form of horse, 
rather high, and with three legs instead of tlie usual two. The braces 
are all put on the inside to leave the surface clear, while the support¬ 
ing pins differ only in length. In this case they have been made 



Fig. 75. Dogs with Adjustable Centers for Handling Crankshafts 


long enough and strong enough to hold two or three shafts at once. 
In this way, the one horse can hold some 48 shafts at once. 

Handling Three-Throw Shafts. The rigging just described is 
for four-cylinder shafts only, as these have the throws all in one 
plane, so that, although three different centers are required, they lie 
in one straight line, and the flange can be very simple for this reason. 
With a six-cylinder shaft, on the other hand, this is not the case; 
and a much larger flange is needed, for the three pin centers are 
spread out fan-like around the main bearing center. A form is 
shown in Fig. 74, which can be used for a shaft of this general type, 
although the one shown in the lathe provides for two pins only, not for 
three. For a six-cylinder engine of ordinary crankshaft construction, 
this would have to be like the triangular sketch at the lower right, if 
it is carried out on the same plan; or with the same bearing and pin 
centers, and a round outline as shown by the dotted line, if there was 
no necessity for saving metal. 























































GASOLINE AUTOMOBILES 


83 




Fig. 76. Lapping Fixture of Simple Construction 
for Crankshaft Pins 


Adjustable Crankshaft Flanges. In the small shop the general 
run of work varies so much that the principal difficulty lies in having 
flanges, dogs, or fixtures for handling the variety of crankshafts that 
come in. Diameters vary so much that a wide range of central holes 
is needed, because throws 
are all different. This 
gives a different center 
to center distance; then, 
too, there are still one- 
and two-throw, and 
other old forms of shafts 
in use, which come in 
occasionally for repairs. For these reasons, it is not wise for the small 
shop to go too far into special crankshaft fixtures; it should stick to 
simple dogs, with adjustable center distances, like the three shown in 
Fig. 75. While the shaft indicated is a single-cylinder form, dogs of this 
type can be used on other forms. This constitutes their biggest advan¬ 
tage. The variation in the three is self-explanatory to any machinist. 

Crankshaft Lapping. The pins of a crankshaft need lapping 
the same as other pins where a grinding machine is not available. 
There are two ways of doing this: by hand, which is slower but more 
simple so far as apparatus is concerned; and by machine, which 
requires special fittings for this purpose. In the sketch, Fig. 76, a 
form of hand lapper is shown. This consists of a pair of hinged 
members, with a central 
hole large enough to 
take various sizes of 
bushings, such as would 
be required on different 
shafts. A long handle 
is provided; also a bolt 
to hold the two halves 
together when the bush¬ 
ing has been inserted. 

The babbitt bushing must be split and have end flanges to hold 
the halves in place sideways. The handle gives leverage for work¬ 
ing the tool, which is made effective by the application of fine emery 
and oil on the pins to be lapped. In the same way, the pins are pol- 



Fig. 77. Lathe Set-Up for Lapping Crankshaft Pins 



















84 


GASOLINE AUTOMOBILES 


ished by means of a pair of long wooden clamps, shown below, and 
made in somewhat the same way. There is a hinge at the back; and 
the abrasive used is fine emery cloth, which is flooded with oil. 

The throws on the crankshaft can be lapped in the lathe by 
putting it between centers for the main bearings and by using a 
special flange for the other pins. A method which can be used is 
shown in Fig. 77. This consists of a special fixture, made from a 
large casting with a base to fasten to the face plate; a long extension 
arm, having a split end for attaching and detaching, to encircle the 
throw to be lapped. When this is used, the shaft is supported in 
V-blocks, somewhat flexibly it is true, but sufficiently. 

Welding Shafts and Cases. The welding of broken crankshafts 
and crankcases, such as central breaks, breaks around the cylinder 
supporting surface, bearing supports, and supporting arms will be 
found fully discussed under the subject of welding, with full direc¬ 
tions as to the preparation of the work, the materials, and other details. 

CRANKCASES 

Function of Crankcase. The lower part of the motor car, truck, 
or tractor engine is generally enclosed for the purpose of assisting the 
circulation of the lubricant, and for keeping the dirt and dust out. 
This enclosure is called the crankcase, and covers the crankshaft, 
the connecting rods, the bearings for both, and the lubricating system 
and lubricant reservoir. In general, the crankcase forms the support 
for the entire engine, as arms extend from it for this purpose. It 
also supports the cylinders upon its upper face or faces, and the 
crankshaft bearings upon inner integrally cast bosses. This is worded 
in this way, for formerly many marine engine cylinders, and even 
today, all high-powered marine engine cylinders are set upon posts 
and the sides between the cylinders and crankshaft left entirely open. 

Crankcase Construction. Most crankcases are split longitudi¬ 
nally along the center line of the crankshaft. The upper half sup¬ 
ports the cylinder and crankshaft and the weight of the engine on the 
chassis frame, and also has proper provision for the support of the 
various accessories upon it. The lower half, in such cases, is formed 
as a simple enclosing pan, with oil reservoir in the bottom. When 
the lubricant is circulated by pump, this is generally attached to 
the lower half of the crankcase, either inside or outside. 


GASOLINE AUTOMOBILES 


85 


A. section through a modern crankcase is shown in Fig. 78, which 
illustrates a twelve-cylinder motor. Note the inclined upper sur¬ 
faces of the upper half to which the cylinders are bolted and the 
stiffening rib at the center line where the two halves meet. Note 
also how the lower half is simply an enclosure, carrying only the oil 
strainer (shown) and the oil pump (not shown). It has cooling fins cast 
on its lower surface to keep the temperature of the oil down. The 
shelf, which is cast on the upper half to close the space between the 



Fig. 78. Section through Crankcase of Box Type for Twelve-Cylinder 

V-Type Packard Motor 


sides of the crankcase and the chassis frame, serves the double purpose 
of a protecting pan to keep out road dirt and water and of a supporting 
shelf for accessories. Fig. 79 shows the same engine from the front. 

Crankcases are made mostly in two forms: the box type, which 
has more or less straight sides, with a flat top and bottom; and the 
barrel type, which is round or a modified round with a flat bottom and 
top. The one shown is of the box type; the barrel type is generally 
not split along the center line, but it has removable end plates which 
allow the insertion of the crankshaft and a very simple bottom plate 
which carries the oil supply. The one-piece type is supposed to give 
greater rigidity, but this is at the expense of accessibility. 

Modern Tendencies in Design. There are two modern ten¬ 
dencies shaping toward a modification of, or the entire elimination of. 
































































8G 


GASOLINE AUTOMOBILES 


the lower half of the crankcase as it is now known. One is the mini¬ 
mizing of its functions, so it can be made of pressed steel, when it 
becomes a cover only, and the oiling system is made such that the 
supply is carried elsewhere. The other is the casting of parts of 
the crankcase integrally with the cylinders. This has been done 
successfully with the Marmon, the Ford, and with others, in which the 
cylinder block and the upper half of the crankcase are cast as one. If 



Fig. 79. Assembled Motor Shown in Section in Fig. 78 
Courtesy of Packard Motor Car Com-pany, Detroit, Michigan 


this casting is considered as a cylinder unit, there is no upper half of 
crankcase. By extending this practice a little further, the lower half 
may be combined with cylinder block and upper half, so that the 
crankcase as we know it now would cease to exist. 

All these combinations save weight and reduce cost. They also 
reduce the number of parts and make the car as a whole more simple. 
In some cases they go hand in hand with large production, as the 
pressed steel lower half of the crankcase calls for a big expenditure 
for dies. On the other hand, they may make the repair man’s work 
greater. As, for instance, when the cylinders are combined with the 









GASOLINE AUTOMOBILES 


87 


crankcase, it is an all day’s job to take out a piston and replace it. 
When the cylinders are separate, cast in pairs, or bolted on, a piston 
can be taken out and replaced in a couple of hours. 

Crankcase Materials. It is important that the repair man 
should know the materials of which both upper and lower halves of 
the crankcase and the gear cover are composed, for these may need 
repairing. In general, crankcases are of aluminum alloy, the exact 
composition varying. When this is the material, the gear cover is 
of aluminum alloy also. A few crankcases are made of cast iron, on 
very low priced cars. Others have the pressed-steel oil pan, pre¬ 
viously mentioned. A few high-grade cars have bronze crankcases; 
these are either government bronze or vanadium bronze. 

Crankcase Arms and Engine Supports. The engine is generally 
supported by crankcase arms extended from the sides or ends of the 
upper half of the crankcase and cast integrally. However, this is not 
always the case. In many unit power plants, the rear pair of sup¬ 
porting arms may be fixed to the flywheel housing or to the transmis¬ 
sion case. Moreover, separate supporting members bolted or hinged 
in place may be used. These are heavy steel forgings, stout bronze 
castings, or heavy gage steel tubing. This may be done to allow 
the engine freedom of slight rotation and relieve it of twisting due to 
road inequalities; it may be done because of lack of confidence in the 
strength of the crankcase material as an engine support; it may be 
done to facilitate foundry work on the crankcase, and thus reduce its 
cost; or for other reasons. In taking out an engine, the repair man 
should find out about this, as it may simplify or complicate the removal. 

Gear Cases, or Gear Covers. At the front end of the great 
majority of engines, the gears which determine the working of the 
engine and its accessories are placed. These may include the crank¬ 
shaft driving gear and any or all of the following driven gears: camshaft 
gear, magneto gear, water-pump gear, lighting-generator gear, oil- 
pump gear, and sometimes fan gear and air-pump gear. These may 
be driven directly by gear contact or by means of silent chains. In 
either case the gears are enclosed by a case or cover, variously called 
the gear case, gear cover, or cam-gear cover. This housing is generally 
of as simple a shape as possible, and is bolted in place with as few 
bolts as possible in the lower half of the crankcase, so as to facilitate 
its removal for crankshaft or other bearing inspection or for repair. 


88 


GASOLINE AUTOMOBILES 


Other details of the crankcase parts, not previously discussed, 
will be taken up under the groups in which they belong; for instance, 
camshafts and cams with valves and valve parts; lubricating parts, 
drilling in crankshafts for lubricating purposes, oil passages in the 
crankcase, etc., under lubrication; and others under their respective 
groups. 

Crankcase Troubles and Remedies 

General Nature of Troubles. The most general crankcase 
trouble, aside from bearing trouble, is breakage. The usual bearing 
troubles previously outlined occur as well with main crankcase 
bearings. These require similar attention, and in their handling 
much special apparatus, such as stands, jigs, fixtures, and tools, can 
be developed by the ingenious repair man. Worn main bearings 
cause a knock. If this comes from any one bearing, it can usually 
be traced quickly. The use of the stethoscope is recommended for 
any crankcase or gear-cover noises or troubles. A squeak from any 
part of the crankcase usually means a lack of oil or the rubbing of 
parts which should not rub. 

Mending Breaks. If the case is of aluminum, it should be 
watched carefully for breaks or cracks. If a crack develops, it should 
be drilled, plugged, and welded, as cylinder water jackets. This will 
prevent the crack from spreading. Any fairly large break means 
either undue stress or a weakness in the metal. The latter can be 
remedied by patching, by building up in the welding operation, or by 
the use of a new part. The repair man who is in doubt about his 
ability to repair a break or crack should always consult a welding 
expert, for welding can be done, and is being done daily, which would 
astonish those unfamiliar with the scope of the process. Moreover, 
it is relatively inexpensive. Quite often, a weld which would not cost 
more than $4 or $5, can be made the same day even by a fairly busy 
shop; otherwise it would mean a new case at a cost of perhaps 10 or 
12 times as much, two weeks’ delay or longer for delivery of the order, 
and the additional time and delay of detaching all the old accessories 
and fittings from the old case, and re-attaching them to the new case. 

Cleaning Aluminum. Aluminum can be cleaned, externally, by 
means of a weak sulphuric-acid solution, say not more than 10 per 
cent sulphuric acid. This should be well scrubbed into the surface 
with a stiff brush, then washed off with water. Care should be taken 



GASOLINE AUTOMOBILES 


89 


to wash well enough and long enough to remove all the acid. 
Moreover, it should be kept from clothes or from any wood parts, as 
it is strong enough to attack fabrics and wood. 

I he aluminum oil pan should be cleaned out at least once a 
season, for the strainer will separate a lot of dirt and dust, as well as 
other foreign matter, from the oil in the course of 8 or 9 months. 
I his will be found in the bottom of the oil pump or beneath the oil 
proper, as a kind of slush or sludge. Sometimes it is thick enough 
to need scraping, particularly in sandy country where the car gets 
little or no care. Generally, a kerosene bath will clean it out. This 
is followed by a “once-over” with gasoline to clean off the kerosene 



Fig. 80. Method of Boring Crankcase Bearings with Special Boring Bar 
Courtesy of Pierce-Arrow Motor Car Company, Buffalo, New York 

and the last of the dirt. If any gasoline remains, it will evaporate 
and leave a crankcase which actually is clean. The porosity of 
aluminum emphasizes this need for a thorough cleaning, which is not 
needed so badly with pressed-steel oil pans. 

Machining Crankcases. Generally speaking, the repair man 
will not be called upon to do any machining on crankcases, beyond 
something like chipping or filing, or in the case of a break, patching 
or welding. But in case such a job should come along, it is important 
to know how to handle it, for there is no more important crankcase 
job than the machining of the main bearings. The necessity here 
is to keep them in perfect alignment, and this necessitates machin- 





GASOLINE AUTOMOBILES 


90 

ing all of them at once with a long boring bar, as shown in Fig. 80. 
The method of support upon the flat upper, or cylinder, face will be 
noted, also the holding down blocks bolted to the table of the machine, 
after being bolted to the cylinder studs. The provision for lubricant 
on each one of the boring cutters will be seen in the small copper pipes 
above and at the back. As the average shop does not have a boring 
tool of this kind, this work will have to be approximated. It could be 
done by hand, using the now well-known Martell aligning reamer, 
to ream the bearings out and put in new and larger bushings. This 
also has a series of cutters, much like the boring bar shown, and is 
actuated by hand. So the principal requisite would be a large flat 
surface on which to work. Possibly this will be found at the drill- 
press platen, the planer table, or the working table of whatever large 
machine tool the shop possesses. In this job, the workmen should 
remember that unless the case is held firmly throughout, it is likely 
to give or spring, and this will spoil the whole job, no matter how good 
it may be otherwise. 

In all crankcase repairs, the repair man should remember that 
the case is really the foundation of the engine, and if it is not firm 
of itself and firmly supported, the action of the engine cannot be 
positive nor continuous. Consequently the case should be handled 
with unusual care. Gear-cover troubles are few and far between, 
consisting mostly of breaks or trouble inside the cover with gears or 
driving chains. These will be discussed elsewhere. Usually, too, 
gear-cover lubrication is automatic, that is, one end of the crankshaft 
and crankcase-bearing lubrication system is continued forward to the 
gear cover, so that it gets all the surplus oil. In this way lubrication is 
cared for automatically, but the repair man should take no chances 
on this with cars under his care. He should remove the gear cover 
occasionally for inspection. Gear noises, too, emanate from the timing 
gears and are often due to a lack of lubricant there, or, to not enough 
thick lubricant to deaden the sound. Sometimes the construction of 
a gear causes a ringing noise, according to the form of construction 
used. Often whirring noises from the gear case are caused by burred 
teeth. The repair man can remove the burr with a file. Sometimes 
a chip of metal will get in between two gears and be pressed into the 
softer of the two; from that time on, it will cause noise continuously, 
and will also cut the other gear. 


GASOLINE AUTOMOBILES 


01 


SUMMARY OF GENERAL AUTOMOBILE INSTRUCTIONS 

Q. Into how many main groups can the mechanical parts of the 
car be divided? 

A. Practically all motor cars can be divided into six general 
groups as follows: (1) engine, or power-producing, group; (2) clutch, 
or engine connecting and disconnecting, group; (3) transmission, or 
speed-varying, group; (4) final-drive group including rear wheels; 
(5) steering group for controlling the direction of the car and including 
front wheels and axle; (6) frame upon which all other groups except 
wheels are hung. The body makes a seventh group, but strictly 
speaking it is not mechanical. 

Q. How many sub=groups are there pertaining to the 
engine? 

A. According to their functions, the parts and accessories of 
the engine may be subdivided into 10 groups: (1) cylinders, pistons, 
connecting rods, crankshaft, and other basic parts; (2) carburetion 
sub-group through which the mixture is supplied which enables the 
engine to run; (3) valve group through which the mixture is allowed 
to enter and leave the cylinders at the correct time; (4) exhausting 
system through which the burned gases are led away from the motor; 
(5) ignition system by means of which the mixture in the cylinders is 
ignited at the proper time; (6) cooling system by means of which the 
temperature of the motor is kept down to a point at which it can 
operate safely and continuously; (7) lubrication sub-group by means 
of which the rotating, or rubbing, parts are kept lubricated so as to 
run without friction or heat; (8) starting sub-group by means of which 
the motor is started; (9) lighting sub-group through which the car is 
lighted, not strictly an engine part but closely allied with starting 
and ignition, and because of its drive from the engine and general 
location of its parts on it, it is classed as an engine sub-group; (10) 
flywheel sub-group. The last is really a single unit but its size, 
weight, shape, location, attachment, and other points are becoming 
so important as to warrant separate consideration. 

Q. Why is it necessary to consider each of these separately? 

A. Because their functions all differ. The very things which 
make each group best fitted to its work make it more widely different 
from each of the others. Some groups are so very different as to 
warrant separate consideration, almost as extended as the balance of 


92 


GASOLINE AUTOMOBILES 


the motor group, as, for instance, ignition, starting, and lighting, 
which naturally group together. 

Q. What are the most popular cylinder forms? 

A. Automobile engine cylinders are mainly of the following 
forms: (1) cast in pairs; (2) cast in block; (3) cast in threes, in the case 
of six-cylinder motors. The last is really a modification of the first. 

Q. What are the advantages of each of these? 

A. The cast-in-pairs form can be removed by one man and 
replaced by two, if it is broken, cracked, or damaged; replacement 
is less expensive; the casting is less complicated, consequently there is 
less waste in the foundry; they are easier to machine, store, ship, 
handle; they also have other advantages. All these apply to the 
cast-in-threes modification. The cast-in-block form makes a more 
simple looking engine, a shorter and more compact one, and renders 
alignment and spacing more accurate and permanent. Furthermore, 
all water, inlet, exhaust, and other connections may be cast integral, 
which is not possible with the cast-in-pairs or cast-in-threes forms. 
Similarly, the crankcase may be cast integral if desired. 

Q. How is the weight of reciprocating parts lessened? 

A. In the case of pistons, this may be done in one of three ways: 
(1) the form, shape, size, and material may remain unchanged, while 
the walls are machined thinner, or ribs are eliminated; (2) the material 
may be changed to a steel which can be machined thinner and smaller 
everywhere, thus saving a material amount; or (3) the material may 
be changed to an aluminum alloy which is lighter throughout, is 
strong to stand machining very thin in some places, and is so ribbed 
as to stand casting very thin in others. The first assumes that cast 
iron is retained; the second calls for a high quality of forged steel and 
is most expensive, so that it is used only on racing cars or cars of 
unusually high prices. The last is fast becoming the general 
method. 

Q. What is the modern tendency in piston rings? 

A. The experiences of aircraft engines and those in racing cars 
have taught that two well-made and w r ell-fitted rings are sufficient. 
This is being applied rapidly to all motor-car engines by the removal 
of the extra and superfluous rings. Many motors had this number 
previously with an oil ring at the bottom, but it has been found that 
the removal of this makes little difference. 


GASOLINE AUTOMOBILES 


93 


Q. Is there a noticeable tendency toward simplicity in connect= 
ing=rod constructions? 

A. Yes, the same as in pistons and rings, toward simplification 
and lightening of the weight, with the removal of all superfluous 
parts. Two bolts are becoming the standard for the big end. The 
H-section machined all over is almost universal, smaller sections being 
used than formerly. Pressed-in wrist-pin bearings of comparatively 
thin walls are being used and a better class of material generally, 
which allows lighter weight and smaller sizes for equal or greater 
strength. Lubrication scoops are being machined-in in the forms of 
holds, and a simple projecting lip instead of former brass tubes, 
which were added. 

Q. What is the accepted type of connecting=rod big=end 
bearing? 


A. The split, or two-piece, form with a shell or backing of 
bronze and a facing, or wearing surface, of babbitt with oil holes 
drilled through and the interior surfaces oil-grooved to and from these 
to distribute the oil evenly. 

Q. Why is this the accepted form? 

A. The bronze backing or shell gives the desired stiffness and 
permanence, also machines well and resists overheating well. The 
babbitt facing, when worn, is easily replaced by any repair man, and 
it will melt out in case of lubrication neglect so little harm is done, 
yet when well-fitted it gives a fine bearing surface. The system of 
drilling and grooving supplies a film of oil at all times. These 
materials and this arrangement supply an almost ideal combination 
when well-made and fitted, hence their wide acceptance. 

Q. What difference is noted in V=type engine bearings? 

A. When the two rods of a V-type engine act upon a single 
pin, the arrangement of the bearings must be such that one must be 
notched out, or divided, to make room for the second, or else the 
exterior of the first must be formed as a bearing surface for the second. 
In the former case, the one bearing is practically in four parts; in the 
latter, the exterior of the inner bearing becomes as important as its 
interior surface, since it acts as the bearing pin for the outer rod. 

Q. Name two general forms of crankshaft today. 

A. The single-plane type and the multi-plane type. In the 
former, as used on four- and eight-cylinder engines, all pins, bearings, 


94 


GASOLINE AUTOMOBILES 


and webs are in one plane. In the latter, as used on six- and twelve- 
cylinder engines, the pins are in three planes set at an angle of 120 
degrees with each other. 

Q. How many different forms of four=cylinder shafts are 
there? 

A. There are but three radically different forms of four- 
cylinder crankshafts, depending upon the bearings. These are: 
(1) The shaft in which there is a bearing on each side of each appli¬ 
cation of power, or five bearings in all; (2) the form in which there is a 
bearing at each end and one in the middle, or three bearings in all; 
(3) the form in which there are no center bearings, but only the 
two end bearings. The first is used on the highest-priced four- 
cylinder cars, because it is expensive of itself and has a similar 
influence on other parts, notably bearings, crankcase, etc. The 
second is in wide use; being the most popular form. The last 
is used only when extreme compactness is desired. There is an 
odd form of shaft in which four bearings are used, but only one 
maker ever used it. 

Q. What is the difference in the average of six=cylinder crank= 


shafts? 

A. Six-cylinder crankshafts differ about the same as fours, 
according to the number of bearings. There are the same number 
of different forms as follows: (1) with seven bearings, or one on each 
side of each application of power; (2) with four bearings, or one at 
each end and one between each pair of cylinders; (3) with three 
bearings, one at each end and one in the middle, used only with block- 
cast cylinders. 

Q. What can you say of eight=cylinder crankshafts? 

A. These vary the same as fours in general, the eight-cylinder 
motor having a four-cylinder shaft with perhaps slightly longer pins 
and of slightly larger diameter throughout. 

Q. How do twelve=cylinder shafts vary? 

A. They are the same as six-cylinder shafts, with the same 
variations as to bearings; in fact, all twelves have six-cylinder shafts 
with slightly longer and larger pins. 

Q. Does counterbalancing effect the shaft? 

A. No, except in outward appearance. The counterbalanced 
shaft is just the same as the shaft without counterbalancing masses. 


GASOLINE AUTOMOBILES 


95 


The general type is the same, also the number of bearings. This 
applies to fours, sixes, eights, twelves, or to any form. 

Q. What are shims, and for what are they used? 

A. Shims are very thin pieces of metal placed between the 
two halves of bearing caps for the purpose of giving a quick, simple, 
easy adjustment when the bearing wears. In theory, this works as 
follows: When a bearing has worn down two inch, the cap is un¬ 
screwed and removed, and shims of a thickness of two inch are taken 
out on each side. Then the cap is replaced and tightened, and the 
bearing is as good as new. In actual practice, the removal of the 
shims creates a shape of bearing which is not an exact circle, so that 
some slight scraping with very little wear, is necessary, as illustrated 
above, and a great deal of rescraping and refitting (in addition to 
shim removal) with greater wear. 

Q. For what is a crankcase used? 

A. The crankcase is used to support the cylinders and the 
crankshaft; to act as a housing to keep out dust and dirt and as a 
retainer and reservoir to hold the oil in. 

Q. What is its general shape? 

A. Generally, crankcases are either of the box shape or of 
the round, or barrel, type. The first named is generally split 
horizontally along the crankshaft center line; has a flat top and bot¬ 
tom, with vertical sides; has the bearings supported in the top half 
only, the bottom acting simply as an oil pan. The second form is 
generally in one piece with removable ends in which two of the shaft 
bearings are located; has a rounded bottom in which th^ oil is held; 
has a flat top but rounded sides. 

Q. Of what material is the crankcase constructed generally? 

A. Aluminum and aluminum alloys are most widely used, 
although there are a number of motors with cast iron, some with a 
cast-iron upper half and a pressed-steel or aluminum lower half, and a 
few of bronze. The latter is expensive and is losing ground. Pressed 
steel is suitable only for quantity production, while cast iron is losing 
ground except in those up-to-date designs in which the upper half 
of the case is combined with the cylinder block. 

Q. How are crankcases supported on the frames? 

A. The most general method on pleasure cars is the casting 
of arms, generally four, integral with the crankcase, these extending 



96 


GASOLINE AUTOMOBILES 

\ 

out to and resting upon the frame, to and through which they are 
fastened. Generally, too, a thin web is cast between the front and 
the rear arm on each side, extending out horizontally from the sides 
of the case to the frame. This serves the double purpose of replacing 
the underpan and of acting as a stiffener for both arms and case. 
On a few cars and on quite a few trucks, a pivoted cross-arm 
is used at the front and a bolt cross-arm at the rear (or vice 
versa), these being forged members. In this way a three-point 
support is obtained, which yields as the frame is twisted or raised 
unequally. 

Q. What is the gear cover and what are its functions? 

A. It is the removable cover at the front end of the engine, 
which covers and protects the camshaft and other gears or silent- 
chain drives. In addition to keeping out dust and dirt from these, 
it minimizes the unavoidable noises which they make and retains 
the lubricant. It is generally a light aluminum shell held on by a 
dozen or less bolts. 

Q. What is the general method of lifting an engine out of the 
frame? 

A. By a rope or a chain sling, hoisted from above by a chain 
hoist, block and tackle, overhead crane, or movable floor crane. 
The latter are of recent introduction but have the advantage over the 
overhead form that they can be rolled around the garage or repair 
shop to any needed point, while the overhead form is useful only 
under its track or runway. In addition, they can be put into use 
more quickly on a rush job, take up little room, and cost no more than 
the overhead built-in form. 

Q. How are engine stands useful? 

A. They hold the engine in a convenient place and at a reason¬ 
able working height. They hold it firmly so that pressure can be 
exerted if necessary or hammering can be done. Moreover, if rightly 
constructed, they allow rotating the engine to do work upon the sides 
or bottom. In these and other ways they save much time and 
trouble, hasten the work, and thus cut the cost. In addition, their 
convenience allows of doing better work. 

Q. Is there any best method of removing carbon from cylinders? 

A. The method depends upon the design and the construction 
of the motor, the quantity and the hardness of the carbon and its 


GASOLINE AUTOMOBILES 


97 


location in the cylinder, and, in part, upon the facilities which the 
shop possesses. The best method varies with almost every case. 

Q. What is the most rapid method? 

A. Probably burning out with oxygen is the quickest method, 
when the shop possesses an oxygen-burning outfit. The spark 
plugs are removed and their holes plugged, one or more valve caps 
are removed to allow working, the gas is turned on and lighted, when 
the workman can do a cylinder thoroughly in three or four minutes. 
This means that the entire process of doing an engine will not take 
over twenty-five to thirty minutes. Any other process will take twice 
as long as this. 















































GASOLINE AUTOMOBILES 

PART 1L 


ENGINE-GROUP ELEMENTS- -(Contin ued) 

CARBURETORS AND CARBURETION 

Function of the Carburetor. As has been pointed out in the 
general outline of the motor car, the first and most important thing 
in the engine cycle is to get the fuel into the cylinders. This is done 
through the medium of the carburetion system, the principal unit 
in which is the carburetor. The function of this is to convert a 
liquid (gasoline) into gas (gasoline vapor) measure this, and add 
to it the right quantity of air to give proper and complete combustion. 
If this be not done, power is lost, either through the use of too much 
or too little air. In the latter case, not all the fuel is vaporized, hence 
some of it is wasted. 

This sounds like a simple proposition, yet its very simplicity has 
been the undoing of many automobile experts. The vaporizer 
becomes more and more complex each year, constant additions and 
changes are being made in the other parts of the system, and in other 
ways the carburetion system shows a constant change. Despite all 
this, few fundamental laws have been found to be in error, and few 
new ones have been discovered or developed. 

Effect of Heavier Fuels. For some years past there has been 
under way a subtle change in the character of the fuel—the gasoline 
used for the propulsion of automobiles. The small production and 
the increasing demand have combined to render almost unpurchas- 
able, except at high prices and then from large dealers, the lighter 
and more volatile gasolines of some years ago. In the place of them 
there have been quietly introduced much heavier petroleum dis¬ 
tillates, which evaporate less readily—though they are actually of 
higher value in terms of power units. This condition has compelled 
several changes in the carburetor problem. 

In addition to the foregoing, in some parts of the world there 
have been serious efforts made to utilize in automobile motors 




100 


GASOLINE AUTOMOBILES 


alcohol and benzene (not benzine), which, with proper provision for 
their carburetion, constitute excellent fuels. 

The most important of the changes dictated by this development 
in the fuel situation is the now general practice of heating the float 
chambers of carburetors, either by water from the circulating system 
or by exhaust gases. An alternative scheme is that of drawing of the 
air for the carburetor from a point adjacent to the exhaust piping, so 
that this air is sufficiently warmed to readily take up the gasoline 
necessary to constitute a proper explosive mixture. 

Jacketed Manifolds. A subsequent and very successful method of 
handling the heavier fuels is that of jacketing the upper portion of the 
inlet manifold, and the circulating of the hot water in the cylinder¬ 
cooling system through this. By having this jacket close to the point 
where the gaseous mixture enters the cylinder, any remaining particles 
of liquid fuel are vaporized before entering the cylinders. In a few 
instances, the same effect is obtained by incorporating the carburetor 
in the cylinder water-jacket casting. In still others, where the car¬ 
buretor is placed on one side and the inlet valves on the other, there is 
a cored inlet passage through the cylinder block between the cylinders 
which heats the mixture, with the same result as stated above. 

Fuel Injection. Systems of fuel feeding by direct injection of 
minute quantities of the combustible liquid into the cylinders or 
into the intake piping have been advocated or experimented with 
for many years, and have found very successful application in station¬ 
ary and flight engineering, though as yet not one of these sytems has 
successfully competed with the carburetor in automobile service, 
where the conditions of power variation are such that fuel injection 
has not seemed readily applicable. 

Nevertheless, there are many engineers who adhere to the view 
that sooner or later fuel injection will supplant present systems of 
carburetion, and progress made recently with aviation motors of fuel- 
injection types may seem in some measure to justify this view. 

Despite the success of this system on aeroplane and stationary 
engines—notably on the Antoinette and the Diesel, respectively— 
there is not, to the writer’s knowledge, a single American motor-car 
manufacturer now using or experimenting with fuel injection. A few 
years ago a motor car brought out in the Middle West used it, but 
this was short-lived. Since then, nothing has been done. 























GASOLINE AUTOMOBILES 


101 


More Valves vs. Forced Induction. The present-day tei^lency 
toward the use of many valves, four per cylinder, seems to indicate 
a necessity for getting more gas into the cylinders in order to get 
more power and speed from the same size of motor. This would 
seem to lead back to the subject, agitated a few years ago and dropped 
for lack of interest, of the need for forced induction. This will 
introduce a greater quantity of gas into the cylinders without resort¬ 
ing to the complications and trouble-breeding possibilities of four 
valves per cylinder. It differs widely from fuel injection, consisting 
in its simplest form of a special form of fan or blower to drive the 
vaporized fuel into the cylinders. 

Classification of Carburetors. Carburetors, as a whole, may be 
divided into three classes: the surface form, in which the air 
passing over the surface of the fuel picks up some of it, mixes with it, 
and produces an explosive vapor; the ebullition, or filtering, type, in 
which air is forced through a body of fuel from below, absorbing 
small particles so that when it reaches the top and is drawn off, it is 
suitable for use in the cylinders; and the float-feed, or spraying, type, 
under which head nearly all modern devices come. The others have 
gone out of use, as fuels today are too heavy for them to be practicable. 

The original float-feed carburetor consisted of one part besides 
the fuel pipe, float chamber, and passage to cylinder, which made it 
remarkable for its simplicity. It had no adjustments, nor was there 
any way of securing an even and continuous flow of fuel or of air, except 
as the engine suction produced these. The need for these qualities 
brought out, one by one, the modifications of the original; and through 
continuous modifications and recombinations of these, all the modern 
devices have been developed. 

Defects in the Original Are Not Found in Modern Types. The 

original carburetor had no adjustment; the opening in the casting 
measured the amount of air, while the size of the nozzle measured the 
amount of the fuel and the fineness of the spray. There was no 
means of regrinding the float valve, and thus no way of assuring 
an even and continuous flow of fuel. The modern adjuncts of the 
original Maybach device consist of remedies for these defects, and, 
in addition, a proper means of balancing and adjusting the float. 

To pick out a modern carburetor at random, take the one shown 
in Fig. 81. Like its ancestor, it has a gasoline chamber into which 



Fig. 81. Strom'berg Model “L” Carburetor 
Courtesy Stromberg Carburetor Company , Chicago 

























































































GASOLINE AUTOMOBILES 


103 


the fuel is admitted by the action of a float, when it first passes 
through a strainer. From the float chamber the liquid passes up to 
and through the spraying nozzle. The weight of the float is so calcu¬ 
lated that the level in the final nozzle is just 1 millimeter (0.04 inch) 
below the top. This insures that there will always be fuel there for 
the air suction to draw off. As the physical action of changing a 
substance from a liquid to a gas is usually accompanied by the 
absorption of heat, it is advisable to supply a reasonable amount 
of this, and thus assist the change of form. In the older Maybach, 
this was inadvertently done by placing the whole apparatus in close 
contact with the hot cylinder. In the modern carburetor, placed 
some distance from the heated portions of the engine, this additional 
heat is supplied by the jacket water. An alternate scheme is to 
pre-heat the air supply by a special pipe from the exhaust manifold. 

From this mixing chamber the mixture of air and gasoline vapor 
passes upward into a secondary mixing chamber. This communi¬ 
cates with the inlet pipe through the medium of the throttle valve. 
The auxiliary air supply, when used, has access into the secondary 
chamber through the auxiliary air valve. This comes into action on 
very high speeds when the engine is pulling very strongly. At this 
time the proportion of gasoline to air is likely to be too large, so 
the auxiliary opens, admits more air, and thus dilutes the mixture. 

Throttle Valves. Butterfly Type. Whatever the nature of 
the mixture in the carburetor, it is admitted to the cylinder by the 
throttle valve, which may take the form known as the butterfly. 
This is a flat piece of sheet metal, preferably brass, attached to a 
suitable shaft with an operating lever on the external end. 

Piston Type. Besides the butterfly type there are fully as many 
of the piston type. The sliding form is a cylindrical ring or shell of 
metal, which is free to slide in a corresponding cylindrical chamber. 
In the walls of the latter are a number of apertures or ports which 
the longitudinal movement of the piston either uncovers or covers as 
the case may be. Sometimes, to facilitate this action, the sides of 
the piston are grooved or notched, but this does not alter the prin¬ 
ciple of sliding a cylinder within another cylinder to cover or uncover 
certain ports in the cylinder walls. 

In addition to the sliding piston, there is the rotating piston, 
working in practically the same manner, that is, its rotation connects 


104 


GASOLINE AUTOMOBILES 


openings in the piston walls with the interior of the vaporizing chamber 
on one side and with the inlet manifold on the other, the amount 
of the opening depending upon the distance the piston is rotated. 

Needle Valves. Needle valves—or spray nozzles as they are 
sometimes called because of the function they perform constitute 
an important part of every carburetor, or liquid-vaporizing device. 
It might be thought that so long as there is a hole by which the fuel 




Fig. 82. 


Valves and Spray Nozzles 



can enter the vaporizing chamber that is sufficient; yet such is far 
from the case. In addition to the function of an entering hole, the 
needle has the additional duty of breaking the fuel up into a fine 
spray or mist, the particles of which are easily picked up by the 

inrushing air, and as 
easily converted into a 
vapor. Therefore, that 
shape, form, or arrange¬ 
ment which will divide the 
» 

entering liquid up into 
the finest particles will be 
the most efficient. The 
difference of opinion on 
this latter point has 
produced the large number of shapes of nozzle and needle which are 
now in use. 

Simple Vertical Tube. In general, practically all these can 
be divided into four groups, illustrated in Fig. 82. The one at A 
is a simple round vertical tube with an opening in the top, through 
which the liquid may pass out. It does not alter the type if the 
sides of the opening converge, diverge, or are straight, but it will 
influence the resulting spray somewhat. Of the twelve makes shown 
with this type, practically all indicate the opening as straight, but 
this may be due to the small size of the drawing which does not make 
the taper apparent. 

Internal Needle Type. Type B, Fig. 82, is similar to the first, 
except that an adjustable pointed needle is added on the inside. 
This occupies most of the center space, forcing the liquid to pass out 
in a smaller circular sheet or stream than would be the case with 
Type A, considering equal-sized holes. In addition, the fact that the 
internal needle valve may be raised or lowered allows this stream 


























GASOLINE AUTOMOBILES 


105 


to vary greatly, both as to quantity of fuel flowing, and the extent 
to which it is spread out. When the needle is down very low, only 
its point enters the hole, so that practically the full area of the latter 
is available, the central needle influencing the column of fuel passing 
out only to make it hollow in the center. 

\\ ith the needle raised to nearly its maximum height, however, 
the point projects clear through, and the needle shaft almost fills the 
lower part of the hole. This reduces the flow to a very fine hollow 
column of spray, as the shape of the needle and of the lower edge 
of the hole is such as to force it inward and then outward so that as it 
leaves the top of the hole it is diverging widely. Thus, the effect 
of the addition of the needle is to allow the use of much smaller 
quantities of liquid with the same-sized hole, of diffusing it more 
widely, and of making it adjustable to varying needs. Despite all 
its advantages, only three of the carburetors and vaporizers shown 
use this type; and of these, one is a combination of this with A. 

External Needle Type. The third type shown at C, Fig. 82, is an 
inversion of B in that the needle is made external and descends from 
above into the hole in the nozzle. In this form, the shape of the 
needle point produces the desired diffusion and spraying effect, which 
accounts for its popularity. Of the models shown herewith, nine are 
of this kind, one being a modified combination of this form and A. 

External Sectional Needle Type. The fourth form, shown at D , 
is like C, except that instead of a needle resting upon the upper 
surface of the hole and allowing a continuous hollow stream of fuel 
to flow, a series of holes break up the column into a number of very 
much smaller columns, each with its own opening. In this form the 
central member may be movable or not, while the holes may be set 
at any angle. Of the examples of this form shown in this article, 
three in all, every one has the holes placed horizontally instead of 
inclined to a vertical, as shown in Fig. 82. Of these, two show a com¬ 
bination of B and D. This is an effective combination. 

Floats. Another feature of the earlier forms of carburetors, 
which was soon found to be in need of a change, was the arrange¬ 
ment of the float. In Maybach’s original vaporizer, there was no 
means of balancing the float; consequently, there was no way of 
preventing wrenching and breaking of the needle-valve spindle. As 
this disarranged the gasoline supply, it made a change very important; 


106 


GASOLINE AUTOMOBILES 


and this problem received early attention. There was also the neces¬ 
sity for reliable devices to regulate the supply of air and of gasoline 
spray from the nozzle, either by original adjustment, by means of 
a governor, or by effecting a constant variation by hand to meet 
constantly varying conditions of engine demands. 

These additions to the original form caused some trouble. 
The ordinary way of managing the balancing of the float, while it 
may be the cause of trouble at times, is a very simple one. The float 
is of exceeding lightness, whether made of cork or metal. With 
the inflow of gasoline in liquid form this float rises, and in so doing 
it strikes against a pair of small pivoted levers near the top of the 
float chamber. The other ends of the pivoted levers rest upon a 
form of shifting collar on the needle-valve stem. So, when the float 
rises above a certain level, it automatically shuts off the flow of 
gasoline by pressing against the pivoted levers, which, in turn, act 
against the stem and press it down until the flow is cut off. The 
float will stay up until the suction of the engine has lowered the 
gasoline level so that the dropping of the float releases the levers 
which raise the needle valve off its seat. The gasoline flow is thus 
automatically regulated by this balanced-float arrangement. 


ADJUSTMENT OF AIR AND GASOLINE SUPPLY 

Methods of Handling Fuel Spray. Probably no one detail 

of the whole list of carburetor parts has caused, and still does cause, 
more difference of opinion than the source of and adjustment of the 
air supply, and its companion, the adjustment of the gasoline spray. 
The latter drew attention long before the former; in fact, the 
former is more of a modern appliance. The fuel spray was inves¬ 
tigated long ago; for the gasoline spray had no adjustment, but 
the size and the location of the level of the nozzle were fixed. The 
spray itself, however, received special treatment. It was projected 
against a conical spray deflector which served to break up the 
column into finer and more diffused particles. In this way, greater 
vaporizing action was gained. 

Water=Jacketing. Longuemare was among the first to use a 
water jacket around the vaporizing chamber. The conversion of a 
liquid into a gas is an endothermic reaction and requires heat for its 
completion. If this is not supplied by external means, it will be 


GASOLINE AUTOMOBILES 


107 


extracted from surrounding objects. This accounts for the frost 
which gathers on the outside of the mixing chambers of carburetors 
which do not have a water jacket or other source of heat supply. 
The heat is abstracted from the air so rapidly that the moisture in 
the air is frozen, appearing as frost on the outside of the carburetor. 

Auxiliary Air Valve. The auxiliary air valve has always caused 
discussion, its opponents claiming that it means extra parts, and 
therefore more adjustments and more sources of trouble; while those 
favoring it say that without some additional means of this sort for 
diluting the mixture at high speeds, it is impossible to run the engine 
fast, as high speed will then mean an over-rich charge. Be that 
as it may, the fact remains that the weight of opinion lies with the 
auxiliary valve. 

Necessity with Heavy Fuels. Practically all the more modern 
vaporizers use an auxiliary air valve, as this is a partial necessity 
with the heavier fuels. That is, it has been found that the heavier 
fuels require more air to vaporize them than can be supplied by the 
primary air inlet. Moreover, these heavy fuels require considerable 
additional heat in order to vaporize, and the auxiliary air inlet has 
been made the vehicle for conveying this. As will be explained in 
detail later on, this is generally connected with the exhaust manifold 
in such a way that the air entering through it is heated to a high 
temperature. Adding this after the fuel has been split up by the 
spraying nozzle and the primary air has proved very successful. 

Usual Forms of Auxiliary Air=Inlet Valve. I he auxiliary U/ii 
inlet usually consists of a simple valve, opening inward, held in its 
place by a spring of a certain known tension, d he strength of the 
spring is carefully determined so that at the proper moment—when 
the motor requires more air in proportion to the amount of gasoline 
use( l_ t } ie valve will open just enough to allow the required amount 
of air to enter. It will be seen that the time and the amount of 
opening will be controlled by the speed of the engine, i.e., by the 
amount of suction produced by the movement of the piston in the 
cylinder. Of course, as the engine speeds up, there is a greater 
piston displacement to be filled per minute, and therefore it is neces¬ 
sary to supply a greater amount ol mixture. I pon changing speed 
suddenly from, say, 500 revolutions to 900 or 1000, the carburetor 
which does not have this device will not give a uniform mixtiue imme- 


108 


GASOLINE AUTOMOBILES 


diately; in fact, it might require a new adjustment of the gasoline flow 
in order to supply the right amount of fuel. What the auxiliary air 
inlet actually does, then, is to control automatically, above a certain 
point, the amount of air admitted, thereby always maintaining a 
homogeneous mixture. In order to prevent any chattering of the 
valve or rapid changes in the air supply, a diaphragm or a dashpot is 
sometimes used in connection with the valve. 

As a substitute for an auxiliary air valve, a number of makers 
have tried the use of steel balls, resting in holes about two-thirds the 
diameter of the ball. By varying the size and weight of the balls, a 
truly progressive action is obtained, for light suction lifts the light 
balls, and strong suction all balls. 

Venturi=Tube Mixing Chamber. Like every other carburetor 
part, the spraying action and the shape or size of the chamber in 
which it takes place have been the subject of much debate. Orig¬ 
inally, the chamber took any convenient shape and varied all the 
way from a perfectly plain cylindrical shape to an equally perfect 
square, with all the possible variations in between. A few years 
ago, however, scientists began to look into the vaporizing and equally 
important measuring action of carburetors, with the result that a 
new shape came into use, which was based upon a scientific principle. 

This is the principle of the Venturi meter used for measuring 
the flow of water, and from its' use the tube, or chamber, having 
this shape has come to be known as a Venturi tube. In form, this 
consists of two cone-shaped tubes diverging in opposite directions 
from a common point, which in the water meter is the point of meas¬ 
urement and in the carburetor is the point of location of the spray 
nozzle. The principle is that if these two frustrums of cones are of 
the proper shape, i.e., include the proper angle and are correctly set 
with relation to one another, the flow of air and gas will be in correct 
proportions to each other at all speeds, assuming first that the air 
enters at the bottom of the tube having the greater angle. 

As a proof of the soundness of the principle of this type of 
vaporizing chamber, it might be said that the majority of carburetors 
in use today have it incorporated in one form or another. Many make 
the upper tube conical for a very short distance, beyond which it 
assumes a cylindrical form. In the true Venturi shape, the usual 
angle at the bottom is 30 degrees, while that at the top is 5 degrees. 


, GASOLINE AUTOMOBILES 


109 


In water meters the contracted area is made one-ninth that of the 
pipe. This same relation, although not exact, holds in the case of 
the carburetor. Since the area varies as the square of the diameter, 
this is equivalent to saying that the diameter of the contraction 
should be one-third the diameter of the full-sized pipe. 

Double=Nozzle Type. A distinctive design of two connections 
leading into the vaporization chamber is the Zenith (French) car- 



^ 

Fig. 83. Zenith Carburetor, Model “O” 

Courtesy of Zenith Carburetor Company, Detroit, Michigan , 


buretor, a diagrammatic sketch being shown in big. 83. I his is but 
a modification, in a way, of the \ enturi plan, for the latter shape 
is actually used for the vaporizing chamber. 1 he new idea consists 
in leading into this mixing chamber, two tubes. Of these, one is the 
ordinary spray nozzle and does not differ from that used on hundreds 

































































110 


GASOLINE AUTOMOBILES 


of other devices. . The second, however, is very different. While it 
leads into the same mixing chamber, it does so through the medium 
of a secondary chamber, or standpipe, to which the suction of the 
engine has access. If this suction is strong, more gasoline is drawn 
into the secondary chamber, from which it may enter the spray¬ 
ing zone. 

The ordinary nozzle is of an exact size and, consequently, can 
pass only a certain amount of fuel, always at the same speed. With 
the additional nozzle, this does not hold; and being of large diameter 
(comparatively), the flow through it depends wholly upon the engine 
suction, which varies at all speeds, often at the same speed upon 
different occasions. 

Use of By=Pass. This matter of two standpipes has a parallel 
in the use of a by-pass, so-called, around the usual mixing chamber. 
On some carburetors this is made so as to allow easy starting, the 
idea being that when suction is applied to the carburetor by cranking, 
with the throttle closed, practically pure gasoline vapor will be drawn 
through the by-pass. This will start the engine after which, as the 
throttle is opened gradually, its movement cuts off* the by-pass, until 
at medium speeds it is out of use entirely. The same thing applies to 
the use of a secondary tube or standpipe for low-speed running. 

A by-pass of a separate nature is made use of for starting and 
priming purposes; this consists of a small separate tank of gasoline 
attached to the dashboard under the hood, with a valve running 
through to the driver’s side for turning on the supply. This is 
connected into the inlet manifold above the carburetor by means of a 
special pipe tapped into the manifold. When it is desired to start the 
motor, it is primed with this device by simply turning on the supply. 
Some gasoline flows into the manifold, and after a few seconds it 
vaporizes. The motor is than cranked over sharply, and a start is 
almost certain. This has the advantage of simplicity, accessibility, 
and low cost. In addition, it is economical of time as compared with 
lifting the hood to prime each cylinder separately. 

Nature cf New Developments. Horizontal Carburetor Outlets. 
Among the newest carburetor features are some which have worked 
themselves out naturallv, and others which have been forced bv 
changes in engine design, in fuel quality, etc. Thus the tendency 
toward block motors, and with it the tendency toward neat lines and 


GASOLINE AUTOMOBILES 


111 


simplicity, has brought forth a general simplification, or elimination 
of inlet pipes, and a fairly wide use of horizontal carburetor outlets. 
1 he latter has affected carburetors by requiring a shorter and more 
compact instrument, with a side outlet and a vaporizing arrange¬ 
ment which will produce tolerably complete vaporization in a 
comparatively short distance. To a certain extent, this horizontal- 
carburetor tendency has modified existing practice in nozzles, Venturi 
tubes, interior areas and arrangements, etc. 

Effect of Heavier Fuels. The growing realization by carburetor 
manufacturers that the increased use of heavier fuels is inevitable 
has brought forth much worthy effort in the way of vaporizing them. 
This has temporarily set aside the kerosene and other heavy-fuel 
vaporizers. However, as the fuel is bound to become heavier and 
heavier, on account of the excessive demands for gasoline, it is only 
a question of a year or so before kerosene and distillate vaporizers 
will be agitated again. 

Effect of Vacuum Feeds. The wide use of vacuum feeding 
devices, combined with the tendency mentioned above to clean 
and simplify, has caused a much higher mounting of carburetors. 
This has always been desirable, but hitherto it has not been possible. 
The vacuum feed for the gasoline supply has made this change pos¬ 
sible, while the cleaning process and simplification actually forced it. 

Effect of Motor Changes. The high-speed form of motor now so 
generally being adopted has had a big influence, as have also the 
multi-cylinder forms, both creating a demand for greater accelera¬ 
tion. Similarly, starting devices have forced the use of a carburetor 
modification by which instant starting is possible. These require¬ 
ments have called for new designs, smaller and lighter parts, more 
nearly complete automatic actions to uncover large air ports, as well 
as other improvements. 

Double Carburetors for Multi=Cylinder Motors. While many 
eight- and twelve-cylinder motors have but a larger-sized plain car¬ 
buretor, the better forms have a double device, each half supplying 
a group of cylinders, and the halves are entirely separate and distinct 
from the other, except for a common fuel-supply pipe. Each set of 
cylinders has its own suction-actuated nozzle and its own independent 
nozzle. This form has shown its worth in actual use, having been 
very successful in aeroplane work on eight-cylinder and twelve- 


112 


GASOLINE AUTOMOBILES 


cylinder motors, and also on a number ol the better eight- and 
twelve-cylinder motor cars. 

Multiple=Nozzle Carburetors. Another development brought 
about by this demand for rapid acceleration, coupled with great 
maximum capacity, has been the swing toward multiple nozzles. 
As has been pointed out on previous pages, there are a number of 
carburetors now with two nozzles. 

Stromberg Carburetors. Fig. 81 shows a cross-section of the 
Stromberg Model “L.” Except that Model “LB,” which is shown 
in Fig. 84, has a horizontal outlet which necessitates the air 
entering from the top and downward, instead of the side and 

upward, these two are almost identical, and the general instruc¬ 

tions which follow will cover both. In general, all the Strom¬ 
berg carburetors are of the so-called plain tube type, that is, the 
air and gasoline openings are plain tubes and thus fixed in size. 
This construction automaticallv meters the fuel by the suction 
of air velocity past the jets, and in addition does away with the 

auxiliary air valve, all the air supply being taken in through a 

single pipe which is heated. Thus, the entire air supply is heated, 
this making for more efficient operation with the present heavier fuels. 

The Model “M” is a vertical, and “MB” horizontal form 
which are similar to the “L” and “LB” models except that they 
are made without the economizer attachment. This alters their 
outward appearance, cross sections, and eliminates one adjust¬ 
ment. That is, the “L” and “LB” have three adjustments, high, 
low, and economizer, while the “M” and “MB” have but two 
adjustments, high and low. To make these points plain in the sub- 
sequent adjustment instructions, Model “MB” is shown in Fig. 85. 

General Instructions. The high speed is controlled by the 
knurled nut “A,” which locates the position of the needle “E,” 
past whose point all the gasoline is taken at all speeds. Turning 
nut “A” to the right or clockwise raises the needle “E” and gives 
more fuel; turning it to the left or counterclockwise gives less 
fuel on the “L” and “LB” models. On the “M” and “MB” 
the instructions are the same except that turning to the left or 
counterclockwise gives more fuel and to the right less. 

If an entirely new setting becomes necessary, put the econ¬ 
omizer “L” in the fifth notch (farthest from the float chamber) 



Fig. 84. Stromberg Model “LB” Horizontal Type Carburetor 
Courtesy Stromberg Carburetor Company, Chicago 
































































































































114 


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GASOLINE AUTOMOBILES 


115 


as an indicator, then turn the nut “A” to the left until the 
needle E reaches its seat as shown by the nut not moving 
when the throttle is opened and closed. When the needle “E” 
is in its seat it can be felt to stick slightly when nut “A” is 
lifted with the fingers. Find the adjustment of “A” where it just 
begins to move with the throttle opening, then give it 24 notches to 
the right or clockwise. In this turning the notches can be felt. Then 
move the economizer pointer “L” back to the zero (0) notch, toward 
the float chamber which will give a rich adjustment. Warm the 
motor thoroughly, then thin down the mixture by turning “A” 
counterclockwise until the motor shows the best power with a quick 
opening of the throttle. This will be the desired adjustment. 

The low speed adjustment is made by means of the adjusting 
screw “B," which controls the jet “K.” The latter passes the 
gasoline in above the throttle and the movement of “B” pro¬ 
vides the necessary air dilution. Screwing “B” in clockwise gives 
more fuel on all models; outward, less. The best adjustment is 
usually i to 3 turns outward from a seated position. This, it 
should be noted, is only an idling adjustment and does not affect 
the mixture above a car speed of 8 miles per hour. When the 
motor is idling properly, there should be a steady hiss in the 
carburetor; if there is a leak anywhere, or one cylinder leaks, 
or if the adjustment is entirely too rich, the hissing sound will 
be unsteady. The adjustment process should be continued until 
a steady hissing sound is produced, for best all-around results. 

As pointed out previously, Models “L” and “LB," Figs. 81 
and 84, have an additional adjustment called the economizer. 
This tends to the use of a leaner mixture, that is, economy of 
fuel, hence its name. To give this desired result, high speed 
needle “E” and nut “A” are raised slightly, the amount of move¬ 
ment being regulated by the pointer “L." After making the high 
speed adjustment for best power with “L" in the zero (0) notch, 
as described previously, place the throttle lever on the steering 
wheel in a position giving about 20 m.p.h. road speed. Then 
move the pointer “L" clockwise or away from the float chamber, 
slowly and one notch at a time, until the motor begins to slow 
down. At this point turn back one notch, that is, the adjust¬ 
ment should be one notch before the point of slowing down. 


116 


GASOLINE AUTOMOBILES 


The amount of this economizer action depends upon the 
quality of fuel, which differs in different parts of the country, 
and also varies with the temperature. Thus, in the Middle West 
the best economizer adjustment will be the third or fourth notch, 
usually. With Pennsylvania gasolines and throughout the South, 
the second notch will prove the best adjustment, while on the 
Pacific Coast no economizer action will be necessary unless dis¬ 
tillate is used. Fewer notches of economizer action will be needed 
in summer than in winter. 

Zenith Carburetors. The Zenith Model “O” carburetor, shown 
in Fig. 83, enjoys wide use in this country because of its simplicity. 
It has fewer ordinary adjustments than any other carburetor 
This is so constructed that but one adjustment, that for slow 
speed, is provided. However, its makers realize that sometimes 
changes and adjustments are necessary to secure proper results. 
They provide for these by the removal of three internal parts 
and their replacement with simpler parts, but with different work¬ 
ing orifices, or holes. 

Zenith Adjustments. The three parts mentioned are: choke 
tube, main jet, and compensator. In Fig. 83, the choke tube is 
marked A". This is really an air nozzle of such a stream-line 
shape (approximating the Venturi) as to allow the maximum flow 
of air without eddies and with the least resistance. When the 
pick-up, or acceleration, is defective and slow-speed running is not 
smooth, the choke tube is too large. In this case, it will be found 
that a larger compensator I does not better the situation. Then 
a smaller choke tube is needed. This is held in place by a screw 
Ah in the choke itself with a lock washer to prevent its jarring 
loose. To remove the choke, the butterfly T must first be 
removed. In the horizontal types, the body is in two pieces, which 
are held together by an assembling nut. When this is removed 
and the two pieces taken apart (the bowl from the barrel), the 
choke can easily be slipped out of the barrel. When the motor 
will not take a full charge, that is, when it cannot, with the throt¬ 
tle fully opened, this indicates the need for a larger choke tube. 
It will be noted that although the pick-up is good, the car will not 
make all the speed of which it is capable. In this case, take out 
the choke tube X , as explained above, and replace with a larger one. 




GASOLINE AUTOMOBILES 


117 


Changing the Main Jet. The main jet G, Fig. 83, shows its 
influence mostly at high speeds. When running at high speed on a 
level road, if the indications show a rich mixture, irregular running, 
characteristic smell of over-rich mixture from the exhaust, firing in 
the muffler, sooting up of the spark plugs, and low mileage, the main 
jet is too large and should be replaced by a smaller one. On the 
other hand, when running at high speed, if the indications are that 
the mixture is too lean, if the car will not attain its maximum speed, 
if there is occasional back firing at high speed, then the main jet is too 
small and should be replaced by a larger one. In respect to back 
firing, however, care should be used, as this is more often due to large 
air leaks in the intake or valves or to defects in the gasoline line. 

To Replace Main Jet. When it is necessary to change the main 
jet G, Fig. 83, to a larger or smaller size, the lower plug L is removed 
first. This has a square head and is removed with a wrench. Then 
the main jet is unscrewed from below by means of a screwdriver, a 
notch being cut into its lower part for this purpose. In reassembling 
care should be taken to see that the fiber joint packing is on the jet 
and that the jet is screwed up far enough to compress this. Otherwise 
gasoline may leak around the threads. But one fiber washer should 
be used. Then the lower plug L is replaced, and this also must be 
screwed up tight. 

Changing the Compensator. The third change which can be made 
is in the compensator I, Fig. 83. The opening in this supplies the fuel 
to the secondary well and, if too large or too small, will have a corre¬ 
sponding influence upon the running of the car. The makers call 
attention to the fact that its influence is most marked at low speeds 
and suggest that when this is suspected, the car should be tried out on 
a hill, regular but long, and of such a slope that the motor will labor 
rather hard to make it on high gear. Under such a test, if the indi¬ 
cations are of too rich a mixture, that is, the same as for a rich mixtuie 
at high speed on the level, as previously explained, the compensator 
is too large, and must be replaced with a smaller one. If the indi¬ 
cations are of a lean mixture, with the motor liable to miss and gi\ e 
a jerky action, the compensator is too small and must lie replaced with 
a larger one. This is easily removed in the same manner as the main 
jet G , by removing the bottom plug beneath it and then ieino\ing / 
with a screwdriver, through the medium of slots for this purpose in its 


118 


GASOLINE AUTOMOBILES 


lower surface. In connection with tin’s last method of adjustment, 
the makers recommend that the workman should start with the 
setting provided, then proceed to determine first the main jet, then 
the compensator, then the choke. In a sense, this method makes 
double work, for any change in the choke calls for a corresponding 
change in the main jet, but it gives superior results. 

Slow-Speed Adjustment. The one adjustment in the Zenith 
device which is really an adjustment and not a change is that for slow 
speed. This is preferably made on the garage floor, with the motor 
properly warmed up. When this has been done and it has been 
throttled down to idling speed, any irregularity, such as the lack of 
ability to throttle down to a really slow speed (say 350 or less r.p.m.), 
calls for a change in the adjustment. When the throttle T, Fig. 83, 
is nearly closed, there is considerable suction at the edge, and the tube 
J in the top of the secondary well P terminates in a hole A near the 
edge of the butterfly at which gasoline is picked up. If the motor 
will not throttle down as slowly as it should, the supply of gasoline 
can be reduced by means of the external milled screw 0. When this 
is turned in, the air entrance N is restricted, and consequently a richer 
mixture is drawn in. When it is unscrewed, or turned out, a larger air 
opening is uncovered, and consequently a leaner mixture is drawn in. 

In this connection, many factors other than the correct slow- 
speed adjustment of the carburetor may prevent good idling. Some 
of these are: too light a flywheel, too much spark advance, and air 
leaks created by (1) poor gaskets, (2) loose valve stems, (3) pitted or 
scored valves, (4) leaky valve caps, (5) spark or valve plugs, (6) leaky 
priming cups, and others. Obviously, if any of these faults exist, 
no amount of adjustment of the slow-speed device on the carburetor 
will give good idling. 

Horizontal Type Adjustments and Changes. Everything that has 
been said thus far applies equally well to the horizontal type shown in 
Fig. 86, except for the adjustment of the idling jet. In this form, the 
idling jet P 2 is supported by the knurled nut 0 which governs the air 
opening for this jet, and replaces the horizontal milled screw 0. 
If a leaner mixture is desired, this is turned to the right, or clockwise; 
tins lowers the jet and increases the size of the available air passage. 
For a rich mixture it is turned the other way, or counter-clockwise, 
reducing the air opening. 


GASOLINE AUTOMOBILES 


119 


Ivloat Removal. In both models, it will be noted that the float 
cover is held on by the spring catch. This is lifted by means of 
its handle, and swung around out of the way. The float cover 
can then be lifted readily by means of the knurled edge. When this 
is removed it should be lifted up straight. The float is then exposed 



Fig. 86. Zenith Carburetor, Model “HP” 
Courtesy of Zenith Carburetor Company, Detroit, Michigan 


and can be removed easily with a piece of wire bent at the end or with 
a match inserted in the center hole. 

Duplex Model Adjustments. The Duplex model, known as 
Model “OD”, is shown in Fig. 87. Although this is an external view, 
it indicates the construction, and it will explain the adjustments 
readily. This has a single float chamber, shown at the left, and a 
single air inlet joined to two separate and distinct spray nozzles, 
with separate Venturis and idling adjustments. The vaporizing 
chambers, or carburetor barrels, are arranged side by side, and the 



































































































































































































































































































120 


GASOLINE AUTOMOBILES 


throttle valves are mounted on the same shaft and work in unison. 
The device is intended for eight- and twelve-cylinder motors and is 
rigged up generally with a pair of separate inlet manifolds, one for 
each group of cylinders. 

Adjustments. The adjustments on this double Model “0” are 
the same as on the single Model “O’. It will be noted that the 



Fig. 87. Zenith Carburetor, Duplex Model “OD” 
Courtesy of Zenith Carburetor Company , Detroit, Michigan 


slow-speed adjustments are through milled headed screws 0. One 
of these projects horizontally on each side, the same as on the single 
model. To make this adjustment, the motor should be started and 
warmed up; then the spark plugs on one group of cylinders are dis¬ 
connected and the slow speed adjusted for the other set. Then the 
process is reversed, with the other set of plugs disconnected, and the 
second group of cylinders adjusted. 

































































































































































































































































































































































































GASOLINE AUTOMOBILES 


121 


As the adjustment is changed, a difference in the idling should 
be noticed. If the motor begins to run evenly or speeds up, it 
shows that the mixture becomes right in proportion, but that 
there is too much of it. This is remedied by changing the butter¬ 
fly throttle position slightly, closing it by screwing out the stop 
screw which regulates the closed position for idling. Care should 
be taken to have the butterfly held firmly against this stop at all 
times when idling the motor. If the single group of cylinders 
being adjusted seems to run irregularly after changing the posi¬ 
tion of the butterfly, another adjustment of the knurled screw 0 
may have to be made. After one group of cylinders has been 
made to idle satisfactorily, the same procedure should be repeated 
with the other group, that is, each half of the motor should be 
adjusted for idling independently to about the same speed. The 
single thing which is radically different and must be remembered 
in this connection is that multi-cylinder engines have very light 
flywheels and reciprocating parts, so the motor is extremely sensi¬ 
tive at low speeds to unequal conditions of ignition, compression, 
and air leaks. This makes it more necessary than with a plain 
four- or six-cylinder form to have the motor in the best possible 
condition before changing the carburetor idling adjustment. 

The Zenith Model “L” is a refinement of Model “0,” just 
described, but all adjustments are made in the way described for “O.” 

Carburetors on Ford Cars. On the Model “T” Ford car, 
there are two very simple forms of carburetor used. They are 
very much alike in general design and construction, but they are 
made by different firms. The form shown in Fig. 89 is the 
Model “G” Holley, while the other form, shown in Fig. 88, is the 
Kingston. Both forms have been used in about equal quantities 
by the Ford Company from 1909 to date. 

In the Kingston (Fig. 88), “A” is the fuel connection, “B” 
the air valve, “C” the low speed tube, “D” the spray nozzle, 
“E” the choke throttle, “G” the drain cock, “H” the lever oper¬ 
ating the choke throttle, “J” the needle valve, and “K” the needle 
valve binder nut. To adjust, warm up the motor, retard the 
spark fully, open the throttle five or six notches on the steering 
post quadrant, then loosen the binder nut K so the needle 
valve “J” turns easily. Turn this valve down with the dash 


122 


GASOLINE AUTOMOBILES 


adjustment, until it seats lightly but do not force it. Then turn 
back away from the seat one complete turn. Let motor run a 
little while, then make the final adjustment. Hose the throttle 
until the motor runs at idling speed, which can be controlled by 
adjusting the stop screw in the throttle lever. Adjust the needle 
valve “J” towards its seat slowly until the motor begins to lose 
speed. Stop and adjust the needle valve away from its seat very 
slowly until the motor attains its best and most positive speed. 
Close the throttle until the motor runs slowly, then pull it open 



Fig. 88. Drawings Showing Construction of Kingston Model “L2” Carburetor 
Courtesy Byrne, Kingston and Company, Kokomo, Indiana 

quickly. The motor should respond strongly. If sluggish, a further 
adjustment may be necessary. Tighten the binder nut. 

In the Holley, A is the thumbscrew with an extension to the 
clutch, by means.of which the needle valve B is raised or lowered. 
The lower end of this projects down into the spray nozzle C, where 
fuel enters from the float chamber J), reaching it through the gaso¬ 
line intake E. To draw off sediment and water use the cock F. 

From the nozzle, the fuel passes up through the strangling tube 
G, where it is met by the entering air from the air inlet //, which has 
been deflected downward and toward the center of this circular space 
so as to pick up the spray of fuel at the nozzle and carry it upward 
in the strangling tube. Then it passes into the mixing tube N, 








































































GASOLINE AUTOMOBILES 


123 


thence out to the motor v ia the mixture outlet I. In this, its quan¬ 
tity is governed by the throttle, the lever of which may be seen at 
J. In the air intake, there is a throttle plate K, which deflects a 
large part of the entering air so that it passes to the right (straight in) 
and is added to the mixture in the mixer chamber. This forms 
the auxiliary air valve. The position of this plate, governed by the 
auxiliary throttle lever L, determines the quantity of both the 
primary and auxiliary 
air, since by its position 
it splits the entering air 
into two parts, one of 
which becomes the pri¬ 
mary air, and the other 
the auxiliary air. For 
low speeds and idling, 
the low-speed tube M 
carries the very rich mix¬ 
ture up direct to the 
mixing chamber and thus 
into the engine. 

Ford Adjustment. 

This Holley model, like 
the Kingston, has but one 
adjustment. The needle 
valve B, which has a pro¬ 
jecting knurled head A 
for turning it, has a con¬ 
ical point C which seats 
into the fuel opening. If 
this is seated, no gasoline 
can enter, but as it is 
screwed out or up an opening is created and increased, which allows 
fuel to flow. The amount of this determines the amount of mixture 
entering the cylinder combustion chambers. Consequently, the 
•primary adjustment with this screw is that of the fuel flow. Air 
enters through the opening II, passes the throttle K, and then mixes 
with the fuel spray, diluting it and carrying it up into the cylinders. 
The amount of the air is governed by the air lever L, its position 



Fig. 81). Section of Holley Carburetor for Ford Cars 
Courtesy of Holley Brothers Company, Detroit Michigan 


















































































































124 


GASOLINE AUTOMOBILES 



B , 

Normal 


being adjusted at the factory. The adjustments as recommended 
by the Ford Motor Company are as follows: 

Initial Adjustment. The usual method of regulating the carbu¬ 
retor is to start the motor, advance the throttle lever (on the steering 
wheel) to about the sixth notch, with the spark lever (also on the 
steering wheel) retarded to about the fourth notch. The flow of 
gasoline should now be cut off by screwing the needle valve down 
(to the right) until the engine begins to misfire; then gradually 
increase the gasoline feed by opening the needle valve until the motor 
picks up and reaches its highest speed and until no trace of black 
smoke comes from the exhaust. Having determined the point where 
the motor runs at its maximum speed, the adjustment should not be . 

changed except as indicated below. 
For average results, a lean mixture 
will give better results than a rich one. 

Dash Adjustment. The gasoline 
adjustment is placed on the dash, 
Fig. 90, the milled head shown being 
fastened to a long rod whose lower 
end is attached to the needle valve 
head A, Fig. 89. Any movement 
of the milled head moves the needle 
valve and gives more or less gasoline. 
After the car has been worked in so 
that it runs satisfactorily, a file mark 
should be made on the face of this milled head to indicate the 
point at which the engine runs most satisfactorily. This is indicated 
by Fig. 90, in which A shows the milled headed rod projecting through 
the dash, and B the mark for satisfactory normal running. In cold 
weather, it will probably be found necessary to turn the finger wheel 
one-quarter turn to the left, or counter-clockwise, as shown at C, 
particularly in starting a cold engine. This movement increases the 
amount of gasoline and makes the mixture richer. In warm weather, 
gasoline vaporizes more readily, and it will be found advisable to 
give the milled head a one-quarter turn to the right, or clockwise, 
about as shown at D. This admits less gasoline and gives a leaner 
mixture. This last adjustment is particularly advisable when taking 
long: rides at high speed for it increases the mileage per gallon of fuel. 




Fig. 90. 


Dash Adjustment of Ford 
Carburetor 


Courtesy of Ford Motor Company, 
Detroit, Michigan 


























































GASOLINE AUTOMOBILES 


125 


Other Ford Models. While the foregoing describes the carbu¬ 
retors used by the Ford Motor Company, there have been many 
different carburetors developed by other companies intended to 
replace the ones just described and supposedly giving better 
results. Practically every large carburetor company has a so-called 
Ford model, while many firms build only carburetors for Fords. 
From which it may be argued backwards that the results obtained 
with the cars as sold are not always entirely satisfactory. A few 
of these carburetors will be described although lack of space pre¬ 
vents a description of many of them. 

Stromberg Ford Model. Fig. 91 shows the Stromberg Ford 
Model, this attaching to the engine in the same way and with the 
same bolts as the regular device, but having a vertical air inlet 
pipe to which a hot air stove and pipe bring heated air from the 
regular exhaust manifold above, down into the carburetor. Aside 
from this difference, this carburetor provides an additional adjust¬ 
ment for the air, and for this purpose a lever is provided which 
clamps around the steering post, this having a wire connection to 
the air valve in the carburetor. The adjustment of this device 
is very similar to, the adjustment of the other Stromberg models, 
previously described. The high speed adjusting nut is marked A 
and the low speed adjusting screw B to correspond with those. 
The same instructions will apply to this, in that it is like the 
“M” models, turning the high speed nut to the left or counter¬ 
clockwise gives more fuel and to the right less. For an entirely 
new setting of this Ford model an opening of 12 notches back 
from a seated position is recommended. 

Toquet Ford Atomizer. An entirely different principle of fuel 
vaporization is used in the Toquet carburetor for Fords, this being 
a very small device, especially designed for, and built only for the 
Ford car. It is shown in section in Fig. 92, this presenting also 
the method of operation. The carburetor consists simply of a long 
air passage in which throttle lever, air control throttle, needle 
valve and atomizer are all placed, and to one side of this the 
simple float chamber. 

In the sketch Fig. 92, air enters at the right, passing the 
choke throttle, and then the needle valve A. This is surrounded 
by a sleeve full of small holes into which the air is forced, then 


126 


GASOLINE AUTOMOBILES 



























































































































































GASOLINE AUTOMOBILES 


127 


passes downward carrying gasoline with it to the fuel channel B 
at the bottom, and thence into the atomizer C. Additional air 
enters the latter at the top, and these two air supplies, combined 
with air pressure along the passage tending to suck the gasoline 
out of the atomizer C, thoroughly and wholly atomize the fuel. 

There really is but one adjustment, that of the needle valve 
A, made by means of the clamp E, which can be connected, if 
desired so as to be moved by the dash milled head of the Ford. 


THROTTLE LEVER ^ 


jONlY ADJUSTMENT £ 

'"-NEEDLE VALVE J\ 


atomizer air cl-LA 

£) INTAKE - "IP I* 
ATOMIZER 

C 



THE NEW 

TOQUFT FEATURE - 
g GASOLINE supply 


Fig. 92. Extremely Simple Toquet Carburetor for Ford Cars 
Courtesy Toquet Manufacturing Company, Westport, Connecticut 

When this is done the instructions for adjustment follow those of 
the Holley or Kingston carburetors just given. Although not pro¬ 
vided by the maker for this purpose, it would seem that the 
secondary air supply, through the atomizer C, might be regulated 
somewhat by means of the atomizer air intake D, which screws 
into place, and consequently can he screwed on or off, more or 
less, this movement admitting less or more air at the bottom ol 
the intake. Moreover, it is provided with a screwdriver slot to 

make this easy. 
















128 


GASOLINE AUTOMOBILES 


Other Holley Carburetors. As has been stated, the carburetor 
illustrated in Fig. 89 and just described is a Holley Model “G”. 
This firm also markets a Model “K ”, which is very similar to the “G”, 
as will be noted in Fig. 93. The biggest differences between these 
models are: the vertical outlet in place of a horizontal; and the 
placing of the needle valve at the bottom because of this. In this 
latter figure, fuel enters by the gasoline pipe through the strainer A, 
past the float valve B, into the float chamber D, the level being 
regulated by the movements of the cork float C. From there, it 
passes through the opening F into 
the nozzle well E, through the 
hole H past the needle to a level 
in its cup-shaped upper end which 
just submerges the bottom of a 
small tube J, with its outlet at the 
edge of the throttle disc K. When 
the engine is cranked with the 
throttle nearly closed an energetic 
flow of air past this point draws 
liquid fuel which is atomized upon 
its exit from the small opening at 
the throttle edge. 

As the engine rotates, consid¬ 
erable air is forced to move through 
the conical passage outside of the 
strangling tube L. The shape of „ 

Fig. 93. Holley Curburetor, Model “K” 

the passage around the lower end Courtesy of Holley Brothers Company, 

P ,. . . i ., . ,, , . Detroit, Michigan 

or this is such that the entering 

air attains its highest velocity, and thus lowest pressure, near the 
upper end of the standpipe M . Consequently, there is a difference 
in pressure between the top and bottom of this pipe, and the air 
flows downward through the series of holes N. At the bottom it 
turns sharply upward, picks up the fuel spray there and passes into 
the main vaporizing chamber above 0, and thence past the opened 
throttle into the inlet manifold at P. 

Adjustment. As will have been noted, there is but one adjust¬ 
ment, that provided by the movement of the needle valve 7. When 
this is screwed to the right, or clockwise, the valve moves upward 







GASOLINE AUTOMOBILES 


129 


and reduces the size of the fuel opening. When turned backward 
to the left, or counter-clockwise, it increases the opening and admits 
more fuel. The effect of these changes in its setting are claimed by 
the maker to be manifest equally over the whole range of the motor. 
According to the maker, this desirable feature is the result of utilizing 
in the nozzle action the pressure drop due to velocity of flow rather 



Fig. 94. Holley Temperature Regulator Attached to Carburetor 


than the pressure drop causing the air to flow. Other Holley models, 
for motorcycles and small cars, are smaller in size, and need not be 

described here. 

Temperature Regulator. 1 his firm recommends a temperature 
regulator for use with its own and other carburetors. This is particu¬ 
larly important now, with the scarcity of fuel, its consequent low qual¬ 
ity, and its high price. It is admitted by all that the heat is necessary 
in cold months, but that it is less necessary, although advisable, in 


































































130 


GASOLINE AUTOMOBILES 


r-VENT HOLE 



warm months. This necessitates a means of varying it. There is no 
better source of heat than the handy exhaust pipe where heat is 
going to waste, so the Holley device, as illustrated in F ig. 94, utilizes 
the exhaust pipe as a source of heat and leads the same to the carbu¬ 
retor through a flexible tube with a regulating valve at the lower, or 
carburetor end. This is regulated by a simple rod connection with 
a small handle which pro¬ 
jects through the dash and 
has a dial behind it. This 
can also be used as a strang¬ 
ling valve to assist starting, 
as shown above at A, for 
hot-air supply in winter, as 
at B, for half cold air in the 
spring and fall months, and 
for all cold air throughout 
the summer months. 

Kingston Carburetors. 

Enclosed Type . The King¬ 
ston enclosed type, as shown 
in Fig. 95, differs from the 
type previously shown in 
that the auxiliary air valves 
in the form of various sizes 
of steel balls are used. 

These are normally seated, 
but they are lifted from 
their seats by increased suc¬ 
tion. The primary air valve 
is not radically different 
from the former model, but the passage of the air is vertical 
rather than at an angle. When the suction lifts the ball valves, more 
air is admitted. This joins the partially vaporized mixture at the top 
of the vaporizing chamber and completes the vaporization and dilution 
before passing the throttle valve on its way to the inlet manifold. Like 
the model previously shown, it has the cup-shaped neecfle recess, so that 
when the motor is shut off, a pool of fuel collects there; this makes 
starting easy, for this fuel is drawn directly in, almost without dilution. 



Fig. 0.3. 


Plan and Section of Kingston Enclosed 
Carburetor 


Courtesy of Byrne, Kingston and Company, 
Kokomo, Indiana 
































































GASOLINE AUTOMOBILES 


131 


Adjustments. If the float is found to be too high or too low, it 
can be adjusted readily by bending the float lever to which it is at¬ 
tached. The only other adjustments are: the setting of the throttle 
which governs the lowest speed, this being accomplished by the screw 
shown on the throttle-lever arm projection at the left; and the setting 
of the needle valve for satisfactory high speeds. This is accomplished 
by unscrewing the cap to which the needle is attached and allowing 
more fuel to flow. Continue until the highest speed is reached and 
passed, then turn back until the maximum speed is reached. 



Fig. 96. Part Section of Kingston Dual Form of Carburetor 
Courtesy of Byrne, Kingston and Company, Kokomo, Indiana 


Kingston Dual Form. This form, as shown in Fig. 96, is really 
two of the enclosed models, just described, attached to a common 
outlet and with a single throttle valve. It is intended for use with 
heavy fuels; one side is connected up for gasoline, which is used in 
starting and for exceptionally slow speeds long continued, while the 
other side is set for heavy fuel, such as kerosene, distillate, etc., and is 
used as soon as the engine running on gasoline has heated up suffi¬ 
ciently. It will be noted that one-half of this device is fitted with a 
water valve, which is placed on the heavy fuel side. It is a gravity 
valve seated by its own weight at low speeds and lifted progressively 
at higher speeds until wide open. In continuous running on heav\ 











































































































132 


GASOLINE AUTOMOBILES 


fuels, it has been found that after a certain time the engine begins to 
pound, but that if cooling water be introduced with the mixture, the 
engine will run cooler, and this pound will disappear. To remedy 
this is the function of the water valve. 

Adjustments. Adjustments and repairs for this model will be 
exactly the same as with the previously described enclosed model, 
since it is simply two of these joined together. As has been stated, 
the added water valve works automatically. 

Kingston Model “L.” The last Kingston model shown, that of 
Fig. 97, is very similar to the Ford model, except that it is formed 
with a vertical outlet, and 
the air valve B added in the 
vaporizing chamber so formed. 

This is hinged at the side so as 
to be swung upward by the 
suction of the motor, thus 
uncovering a larger and larger 
orifice. It is weighted and 
acts automatically. It will be 
noted also that the shape of the 
nozzle has been altered slightly, 
that on the Ford model being 
perfectly straight. Near its 
lower end, it passes through 
the low-speed tube C, which 
has a series of holes around 
the bottom and an annular 
space around the body of the needle. Through this space the fuel 
and a very little air are drawn for starting, as, at that low suction, 
the valve B would be entirely seated. 

Adjustments. After retarding the spark, opening the throttle, 
loosening the needle, and starting the motor, let it run at a fair speed 
long enough to warm up. Then adjust the needle valve. Close the 
throttle by adjusting the stop screw in the throttle lever until the 
motor runs at the desired idling speed. Adjust the needle valve towards 
the seat slowly until the motor begins to lose speed, which indicates a 
weak mixture. Now adjust the needle valvd away from its seat until 
the motor attains its best and most positive speed. This should 



Fig. 97. Section of Kingston Model “L” Carburetor 

Courtesy of Byrne, Kingston and Company, 
Kokomo, Indiana 








































GAS()LINE AUTOM()BILES 


133 


complete the adjustment, (lose the throttle and let the motor 
idle, then jerk it open rapidly. The motor should respond readily. 
If it does not respond, a slight further adjustment may be necessary. 
When the adjustment has been made, lock it. Float troubles may 
be remedied in the same way as for the enclosed model. 

Master Carburetor. The Master is called a carburetor with¬ 
out an adjustment. It was originally developed in Los Angeles 
for the purpose of using the heavy oil, called distillate, which is 
available there. This, as shown in Fig. 98, is a design of remark¬ 
able individuality. Except for the float chamber, it does not 
resemble any other carburetor. In design it consists of a float 
chamber to which the fuel enters from below through a round 
pan-like screen which filters it. From the float chamber the fuel 
passes through another cylinder-like screen which filters it again. 
Then it passes to one end of a long fuel passage, from which lead 
a series of vertical passages, each ending in a nozzle. These pas¬ 
sages discharge the fuel into a cylindrical throttle chamber within 
which is placed a rotary throttle valve. This has a peculiar spiral- 
shaped edge, so that one tube—the end one shown on the right- 
hand edge slightly separated from the others—alone communicates 
with the vaporizing space. This is the starting and idling tube, 
or, nozzle. As the throttle is revolved, the spiral edge brings the 
other tubes into play, one at a time, until the whole number is 
engaged. When the throttle is revolved to the full opening, its 
central portion, as shown in the left-hand figure, is seen to be 
somewhat restricted at the center and flared at the ends to pro¬ 
duce a slightly modified Venturi shape. The passage above the 
throttle leading to the inlet manifold, and the shape of the passage 
below it through which the air enters, both contribute to this effect. 

The air enters from the right, Fig. 98, and the shape of this 
passage, to match the general shape of the carburetor, is low but 
wide. This has led to the development of a variable method of 
furnishing the air; for a division in the end of the passage allows 
of having all cold air, half cold and half hot, or all hot, as desired. 
For the heavy fuel conditions under which the device was devel¬ 
oped, the all-hot air arrangement was used. Except in the hot 
summer months this would be most desirable, but there are con¬ 
ditions under which the semi-hot air arrangement would be best. 




Courtesy of Master Carburetor Company, Detroit, Michigan 


















































































































































































gasoline automobiles 


135 


Adjustment. 'While it is said not to have any adjustment, 
there is a variation which corresponds to the adjustment in many 
carburetors. This is the air damper, which is a long, rigid, flat 
plate extending across the incoming air passage parallel to the 
distributor and is connected by means of a Bowden wire mechan¬ 
ism to an operating lever on the steering post in the position 
where the usual carburetor adjustment is located. When this is 
moved, the air damper is swung over toward, or away from, the 
distributor. This movement restricts or increases the air passage 
at the jets. \\ hen the damper is moved so as to restrict the 
passage of air, its velocity is increased, and the greater suction 
carries up more fuel from the jets, and thereby produces a richer 
mixture. On the other hand, when the damper is moved to 
enlarge the area, there is less suction; consequently less fuel is 
drawn up, and the mixture is leaner. In the sense that the 
operator can change nozzles or modify the maximum or minimum 
amount of air or fuel entering the carburetor, this device has no 
adjustments. The nozzles cannot be changed in any way, and the 
amount of air can be varied only in a wholesale way, i.e., by 
changing from lean to rich through the whole range between these 
two. This device has been used four years as regular equipment 
on Moreland trucks which are built to use distillate selling at 6 
cents a gallon, in barrel lots. This fuel has a specific gravity of 
51 at 60° F. 

When made for Ford cars, this device has only 11 nozzles. 
On the larger sizes from 14 to 19 are employed. The use of this 
device, with its vertical opening, necessitates a special inlet mani¬ 
fold to replace that on the Ford which provides for a horizontal 
carburetor outlet. 

Miller Racing Carburetor. A carburetting device very similar 
to the Master is that shown in Fig. 99, this being the Miller car¬ 
buretor. Proof of its efficiency is shown by its very wide use on 
the highest powered engines, such as the King-Bugatti 16-cylinder 
aeronautic engine, the Duesenberg line of racing and airplane 
engines, and on the majority of recent racing cars. 

As will be noted in the figure (this showing the carburetor as 
used on the King-Bugatti 400-horsepower engine), a number of 
screwed-in jets are used, in the case of this particular engine, the 


136 


GASOLINE AUTOMOBILES 


number being seven, while the number of carburetors used was 
four, one for each four cylinders. In ordinary racing practice one 
or two of the seven-jet carburetors are used. 



Fig. 99. Miller Multi-Jet Carburetor and Altitude Valve Details 
Courtesy //. A. Miller Manufacturing Company, Los Angeles, California 


As the general view and detail indicate, gasoline is drawn into 
each one of the jets through the small hole in the bottom of the 
















































































































































GASOLINE AUTOMOBILES 


137 


threaded end, mixing with a certain amount of air sucked in 
through the four small holes at A drilled in the barrel of the jet 
just above the threaded portion. This air is taken from the out¬ 
side through the upper ^-inch hole B in the jet holder, and 
passes down around the outside of the jet to the four small holes 
mentioned. The major portion of the air enters the carburetor 
through the lower end C of the Venturi, which is 3 inches in 
diameter, passes up around the jet bar holder, combining above 
this with the rich mixture from the seven jets to form the proper 
mixture for combustion. 

This particular instrument being for airplane use, an altitude 
adjustment is necessary, and the details of this are shown in the 
illustration. It operates by turning the lever, and has two open¬ 
ings in its seat which when open register with similar holes in the 
cover giving the free passages to the atmosphere. The float 
chamber is in direct connection with the Venturi through the 
drilled hole D /V inch in diameter, this being well above the fuel 
level. When the altitude control valve is opened, by this means, 
the vacuum in the float chamber is decreased, thus increasing the 
flow of fuel through the jets. 

Like the Master, this has no adjustment, changes in per¬ 
formance being produced by replacing the jets with different ones. 

Webber Automatic Carburetor. The Webber carburetor has 
been produced to meet the need for a very finely and carefully made 
instrument. It is an instrument of precision and is priced accord¬ 
ingly. Two models are made, namely, Model “C,” which has a 
vertical outlet and water jacket; and Model “E,” which has a horizon¬ 
tal outlet and no water jacket and is therefore smaller and more com- 
• pact. With these exceptions, the two are very similar in construction, 
as well as in adjustment. For this reason only the Model “C” will 
be shown. This will be seen in Fig. 100, which shows a longitudinal 
section along the center line of the two chambers. It will be 
noted that this device has a concentric float 37 in which the 
spray nozzle 35 is located. The needle point 32 is controlled through 
the needle-point lever 13 which works down onto it from above. 
The nozzle is placed in the center of the modified Venturi cham¬ 
ber 7, the top outlet of which consists of a series of 10 tapered 
holes. As the fuel mixed with the hot air entering through the air 


138 


GASOLINE AUTOMOBILES 


horn 9 reaches the vaporizing chamber, the auxiliary air enters from 
the side. Because of the shape of the cylindrical vaporizing chamber 




51 and the distance which this chamber extends downward, the 
auxiliary air is forced to turn at right angles and also to pass through 
a restricted area, thus giving it an increased velocity where it picks 





































































































































































































GASOLINE AUTOMOBILES 


130 


up the partly vaporized fuel. In this upper cylindrical vaporizing 
chamber 51 the throttle valve 18 of the simple butterfly type is 
located. 

The auxiliary air enters through the holes 50 below the dashpot 
chamber 3 in which the piston 5 is located. This is attached to the 
upper end of the auxiliary air-valve stem, its lower part having a 
conical extended shape so as to spread out the air. The dashpot 
•prevents fluttering while the downward movement of the air valve 
is resisted by the spring 34. The tension of the spring is adjustable 



Fig. 101. External View of Webber Carburetor, Showing Adjustments 


by means of the milled thimble 28 and the locking plunger 30. The 
air-valve lever 11 is interconnected with the needle-valve lever 13, 
so that any movement which increases the air opening automatically 

increases the fuel flow also, and vice versa. 

Adjusting the Webber. There are two adjustments, aside from 
the setting of the air valve and the determination of the pioper needle 
valve and its correctly proportioned spring. I hese are for low speed, 
or idling, and for high speed, or maximum power. Assuming that 
the carburetor has been installed correctly and the fuel turned on, 












































































































140 


GASOLINE AUTOMOBILES 


the makers recommend turning the air-valve adjusting-spring thimble 
C, Fig. 101, up or down until the air valve upon being pressed down 
and released returns lightly but positively to its seat. Next turn 
the low-speed adjusting screw A down (right handed, or clockwise) as 
far as it will go without resistance, then turn it up, or back, about 
three-fourths turn. Turn the high-speed adjusting screw B to the 
right or left until the fulcrum block E is approximately in the center 
of its travel. Be sure that when the lever of the steering-post control 
(handle operating Bowden wire) is moved down to the lean position, 
the lever F on the carburetor is pressed forward firmly against its stop. 

Low-Speed Adjustment. Move the lever of the steering control 
to the rich position, open the throttle about one-quarter, then start 
the motor. Now move the lever on the steering-column control down 
to the lean position and allow the motor to run idle until thoroughly 
warmed up. If it does not idle properly, turn the low-speed adjusting 
screw A up or down until it runs smoothly with the throttle closed 
against the stop screw D. The latter, after being adjusted properly, 
should be fastened by setting up the clamp screw provided for this 
purpose. This adjustment is for idling only. 

High-Speed Adjustment. The high-speed adjustment is made 
by turning the screw B to the left or right. This moves the fulcrum 
block E in or out; moving it in gives less gasoline at high speed, and 
moving it out gives more gasoline at high speed. This adjustment 
can be made with the motor standing and continued until what seems 
to be the best position is reached; but the final high-speed adjust¬ 
ment should be made on a long hill. On this, start up at the bottom 
at about 20 miles per hour, open the throttle wide, and note the speed 
at the top. Now go down the hill. After moving the fulcrum block 
E out about yq inch, try the hill a second time, starting from the bot¬ 
tom at the same speed as before and noting particularly the speed 
which results at the top. If this shows a gain, move the fulcrum 
block out another ^ inch and try again. If it shows a loss, move the 
fulcrum block in and then try the hill. Continue until the maximum 
speed at the top of the hill is obtained, then lock the adjustment. 
This means but a few trips up and down the hill and results in a 
setting which is permanent and gives maximum power at all times. 
This adjustment is for maximum power only and has no effect upon 
the idling adjustment made previously. Be careful also not to pass 


GASOLINE AUTOMOBILES 


141 


the point of maximum power; as this point means maximum speed, 
flexibility, and acceleration. 

Starting Adjustment. 1 he makers claim that it is unnecessary 
when the proper adjustments have been made to wait for the motor 
to warm up before starting away; simply move the steering-column 
control to the rich position, start the motor, and drive off, then, as the 
motor warms up, move this control lever down toward the lean posi¬ 
tion, running normally with this as far down toward lean as it will go. 



Upper Automatic 
Air Valve 


DASH POT 
L PISTON 


MODEL G 


Gasoline 

Intake 


WATER JACKETED 


Spray 

Nozzle 


Lower Air Valve 


ru— r 

Metering 
Pin 


F. 

Metering 


Pin Nozzle 


Fig. 102. Section of Rayfield Carburetor, Model “G” 
Courtesy of Findeisen and Kropf Manufacturing Company, Chicago 


Except that some of these adjusting screws are located differently, 
the adjustment of the Model “E” is the same as that of Model “C”, 
as is also that of the Model “EH” a modification of the “E” adapted 
particularly to the Hupmobile. 

Rayfield Carburetor. The Rayfield carburetor, Model “G”, as 
shown in Fig. 102, is of the double-needle type, with three air-inlet 
openings and an eccentric float chamber. The latter is shown at the 
left, with fuel entering from below through a strainer. Communi¬ 
cating directly with this float chamber is the passage in which the 
low-speed nozzle (marked spray nozzle) is situated; this consists of a 
hollow member with the actual needle point coming down vertically 



















































142 


GASOLINE AUTOMOBILES 


from outside and above, similar to C, Fig. 82. Communicating with 
the float chamber is a passage, or well, through which fuel flows across 
to the bottom of the high-speed well. In this passage is located a 
hollow metering-pin nozzle; and in the upper part of it is the meter¬ 
ing pin. The upper end, through which the fuel flows, is located in 
one end of the elongated vaporizing chamber, while the upper auto¬ 
matic air valve has access to the top of it and furnishes the air supply. 

At the other end of the vaporizing chamber the idling needle is 
located, and directly beyond it is the constant air opening, a simple 
round hole communicating with the atmosphere. This end is short 
and close to the central portion of the chamber, which is approxi¬ 
mately cylindrical. The lower air valve is at the bottom, while the 
vertical connection to the inlet manifold and the butterfly throttle are 
at the top. The lower air valve and the upper automatic air valve are 
linked together so as to operate simultaneously. The movement of 
the upper automatic air valve downward actuates the metering pin, 
moving it downward; this tends to allow fuel to flow out around the 
pin. At the same time, the stem of this valve is connected at the 
bottom with a piston working in the dashpot which is filled with fuel, 
so that any sudden tendency for the air valve to open is checked by 
this dashpot. At the same time, this piston communicates with the 
hollow metering-pin nozzle, so that the downward movement of the 
piston forces an extra supply of fuel into the nozzle and enriches the 
mixture. Thus, the opening of the throttle automatically produces 
a rich mixture for starting, as the slow movement of the air valve in 
opening against the drag of the dashpot causes a relatively stronger 
suction on the nozzles. This arrangement eliminates the necessity 
for an air-valve adjustment, that is, an adjustment which owner or 
repair man is supposed to use. As a matter of fact the carburetor is 
made with an adjusting ring, which, after setting at the factory, is 
locked by means of a set screw and is not supposed to be touched. 

Adjustments . Referring to Fig. 103, there are but two simple 
adjustments on the Rayfield; both are made by means of external 
milled head screws. Before making any adjustments, be sure there 
are no obstructions in the gasoline line, that all manifold connections 
are tight and free from air leaks, that valves and ignition are correctly 
timed, and that there is good compression and a hot spark in all 
cylinders. These carburetors are generally fitted with dash control. 


GASOLINE AUTOMOBILES 


143 


Always adjust the carburetor with this dash control down. The 
iow-speed adjustment should be made first. To make this, close the 
throttle and let the dash control down, then close the nozzle needle 
by turning the low-speed adjustment, Fig. 103, to the left until the 
block U leaves contact with the cam M slightly. Then turn to the 
light about three full turns. Start the motor and allow it to run 
until warmed up, then push the dash control all the way down, retard 
the spark, close the throttle until the motor runs slowly without 
stopping. Now make the final adjustment by turning the low-speed 
screw to the left until the motor slows down. Next, turn to the right, 



HIGH SPEED 
ADJUSTMENT 

TURN TO RIGHT 
FOR MORE GAS I 


THIS R1NC IS V. _ 
PERMANENTLY LOCKED 
“DO NOT TURN’ 


GASOLINE 

INTAKE 

CONNECTION 


LOW SPEED 
ADJUSTMENT 


TURN TO RIGHT 
FOR MORE GAS 


Fig. 103. External View of Rayfield Carburetor, Model “G”, Showing Adjustments 

one notch at a time, until the motor idles smoothly. If the motor 
does not throttle low enough, turn the stop-arm screw on the main 
throttle-valve shaft to the left until the motor does run at the mini¬ 
mum speed desired. 

High-Speed Adjustment. Advance the spark about one-quarter 
with the motor running, then open the throttle quickly. Should the 
motor back-fire, it indicates a lean mixture. Correct this by turning 
the high-speed adjusting screw, Fig. 103, to the right, about one notch 
at a time, until the throttle can be opened quickly without back-firing. 
If loading, or choking, is experienced when the motor is running under 




















144 


GASOLINE AUTOMOBILES 


heavy load with the throttle wide open, it indicates too rich a mixture. 
This can be overcome by turning the high-speed adjustment to the 
left. Adjustments made for high speed will not affect low speed. 
Low-speed adjustments must not be used to get a correct mixture 
at high speed. Both adjustments are positively locked. 

Changing Nozzles. “Never, under any circumstances, change 
nozzles in the Models “G” and “L” carburetor,” say the manufacturers. 
Neither should the float level be changed, as they say this is correctly 
set at the factory and should not be touched. For use with a pres¬ 
sure system, two pounds pressure is advised. The plugs S, 1, and A 



Fig. 104. Sketch of Starting Primer Attached to Model “N” Rayfield Carburetor 


are for cleaning and draining purposes. In the bottom of the float 
chamber there is a strainer trap, which can be cleaned by shutting 
off the gasoline supply and removing the nut S. The dashpot is 
drained by opening the drain cock X; it is advisable to do this occa¬ 
sionally to remove any sediment that may have accumulated there. 
The float chamber should also be drained occasionally by removing 
the plug Y. When this is replaced, it should be tightened very care¬ 
fully; and when the strainer trap is removed and cleaned, care should 
be taken in replacing it to put the gaskets back in place as well as to 
tighten the nut adequately. 

The Model “L” is the same as Model “G” without the water 
jacket. It is adjusted in the same manner, and all that has been 
































GASOLINE AUTOMOBILES 


145 


said above on the subject of adjusting the 
force to the U L”. 


“G” applies with equal 


Adjusting Model “M ”. The Rayfield firm makes another model, 
known as Model “M”, which is similar to the Model “L”, except 
that it has a side, or horizontal, outlet. It has the same two adjust¬ 
ments, made in the same way, but the shape of the carburetor locates 
these in a different place. The low-speed adjusting screw is on the 
extreme top of the carburetor, and the high-speed adjusting screw 
is also on the top, but it is made accessible by removing the hot-air 
elbow from the main air valve. This model is fitted with a starting 
primer incorporated in the device itself and operated through the 
medium of a dash lever. In the sketch, Fig. 104, which is self- 
explanatory, the construction and operation of this are shown. When 
pressure feed is used, not more than one pound is recommended for 
Model “M”. When the starting primer is to be attached, the following 
method should be used: Locate the position on the dash desired for 
the push button and drill a f-inch hole at the proper angle. Attach 
the adjustment and run the tubing to the bracket on the carburetor, 
avoiding sharp bends. Cut off the tubing so it will extend beyond 
the bracket not more than | inch. Remove the temporary wire 
from the carburetor, insert the tubing and secure permanently by 
tightening the clamp screw. Run the dash adjustment wire through 
the hole in the binding post on the eccentric lever. Then, with the 
push button down, place the eccentric arm in position so that the 
line on the eccentric just comes in contact with the adjusting screw. 
Tighten the screw in the binding post, cutoff the surplus wire, and, 
without changing the position of the push button, make the carburetor 
adjustment, as previously described. 

Ball and Ball Carburetor. The Ball and Ball device has been 
developed by Frank H. and Frederick O. Ball and is named after 
them, but it is manufactured and sold by the Penberthy Injector 
Company. In all its forms, as used on a number of different cars, 


whether single or double, horizontal or vertical, it is a two-stage 
instrument. These two stages are called the primary and the 
secondary. As shown in Fig. 105, the primary stage corresponds to 
the usual simple air-valve carburetor. This consists of nozzle, or 
jet, 3, located in the fixed air passage, or Venturi, 2. In the passage 
above this, it receives its air for complete vaporization from the 


146 


GASOLINE AUTOMOBILES 


valve 4- Some air is, of course, admitted around the nozzle 3 below the 
Venturi 2, otherwise the fuel would not be drawn up. This nozzle 
receives its fuel from the float chamber 14 , which is supplied through 
a strainer in the usual manner from the gasoline pipe 13. The con¬ 
nection from the float chamber to the jet extends first to the well 16, 
thence across the horizontal passage 17, from which the nozzle 3 
draws its supply. 

Now, to this simple carburetor add another which consists of the 
nozzle 6 and of the air supply 5, which is normally closed by the 



Fig. 105. Section through Ball and Ball Two-Stage Carburetor 
Courtesy of Penberthy Injector'Company, Detroit, Michigan 

butterfly throttle 7; this latter, when closed by a spring, covers the 
top of the jet 6 so that it cannot function. It is obvious that the 
primary stage is constructed for low speed, idling, and for the lower 
range of driving, and is very economical. As this lower range covers 
perhaps 85 to 90 per cent of ordinary driving, this would be a desir¬ 
able feature. 

As the drawing shows, the opening of the second throttle valve 
7 allows additional air to enter and, at the same time, uncovers the 
























































































































































































GASOLINE AUTOMOBILES 


147 


second jet 6, so that this starts to function by drawing its gasoline 
from the same horizontal passage 17 as does the primary jet. 
If this throttle be connected up to the other throttle in such a way 
that, when approaching the maximum opening of the main throttle, 
the secondary throttle begins to open, we have, in effect, two carbu¬ 
retors, one working over the lower range, which gives good idling 
and splendid economy, and another high-speed and high-power device 
adding its total effect to that of the primary. The two contradictory 
and opposed qualities of highest power and highest economy are 
thus produced by what is, in effect, a double carburetor. This, 
with variations for various sizes and types of cars, constitutes the Ball 
and Ball device, shown in section in Fig. 105. 

Pick-Up Device. This carburetor has a pick-up device which 
produces remarkable acceleration. This consists of the plunger 8 
having a smaller sized upper end 9. It is loosely fitted in the cham¬ 
ber 15, the bottom of which communicates with the float chamber, 
and is thus kept full of gasoline. iVt the top, a small hole 10 commu¬ 
nicates with the manifold above the throttle, while 11 is an opening 
to the atmosphere, and 12 is an opening to the mixing chamber. 
When the -throttle is nearly closed, the vacuum in the manifold 
raises the plunger, and the space below it fills with gasoline. In this 
position it is ready to act. When the throttle is opened suddenly, 
the vacuum is broken, and the plunger drops of its own weight, forcing 
the gasoline up where it is swept into the mixing chamber by 
the air entering through the passages 11 and 12. This is repeated as 
often as the throttle is suddenly opened from a nearly closed position. 

Adjustments. The primary stage must be adjusted as a whole 
to give the best idling and slow speeds; this consists of the adjustment 
of the air-valve spring, the arrangement of the hot-air passage leading 
to it, or, if these prove insufficient, the changing of the primary 
nozzle. The last change is opposed by the makers. 

Beyond this, the only adjustment possible lies in the hot-air 
choke valve which can be moved or altered from the dash to give 
more or less hot air. The partial closing of this valve makes starting 
easier and helps the running of the motor until it gets warmed up, 
but in normal running its manipulation has little effect. In going 
farther than this, the only possibility lies in altering the design by 
varying the connection between the two throttles, so the second stage 


148 


GASOLINE AUTOMOBILES 


cuts iii sooner or later, but this might impair the usefulness of the 
instrument. The same is true if the secondary nozzle is changed. 
The device, then, is really lacking in adjustments in the ordinary 
sense, except for the initial setting of the primary-stage air valve. 

Newcomb Carburetor. The Newcomb carburetor is made by the 
Holtzer-Cabot Electric Company and is a constant vacuum type 
having a single nozzle and an eccentric float chamber. It is a high- 
grade instrument and is used only on the highest-priced cars. As 



Fig. 106. Section through Newcomb Carburetor' 
Courtesy of IIoltzcr-Cabot Electric Company, Boston, Massachusetts 


shown in Fig. 106, the hot-water-jacketed vaporizing chamber will be 
noted at the left. In the center of it is the hollow plunger 69, which 
works up and down in the plunger chamber 68. The top portion of 
the plunger has the needle holder 73 held in place by the lock nut 74. 
The hollow plunger 69 surrounds a tube at the top of which the fuel 
nozzle 72 is located. The fuel controlling needle 71 is fixed in the 
needle holder 73 and projects through this nozzle down into the 
central fuel well. This is connected by a horizontal passage at the 
bottom to the lower part of the float chamber, seen at the right, 



















































































































































GASOLINE AUTOMOBILES 


140 


which is of normal, or usual, construction, except for the regulating 
cap 77 on the top of the central opening above the float needle 85. 

Around the bottom edge of the plunger 69 a large number of 
holes of small size are drilled, and these are arranged to register with 
an equal number of relatively narrow air slots cut in the bottom of the 
plunger chamber walls. These distribute the fuel after it has passed 
up the central well, issued from the nozzle, and been drawn within 
the plunger. The plunger when at rest is seated on the collar 70, 
which is threaded into the bottom of the plunger chamber and is used 
as a means of adjustment, as will be explained later. This collar is so 
set as to raise the plunger slightly, thus opening the fuel nozzle without 
uncovering the air slots in the plunger chamber. In this way, the fuel 
port is given a lead with respect to the air ports, so that a rich mixture 
is delivered when the plunger is raised a little, as in starting or idling. 

When air is drawn through the carburetor by the motor suction, 
the plunger lifts in proportion to the amount of air entering. This 
lifts the needle and, at the same time, releases the exact amount of 
fuel needed to charge the entering air correctly and thoroughly. The 
higher the plunger is lifted, the greater the air and fuel openings. 
The effective areas of these air and fuel ports are so proportioned as 
to be correct at all positions. The slots in the plunger chamber walls 
being small, the jets of air coming through them have a high velocity, 
so that the fuel is atomized as it issues at these points. Any unatom¬ 
ized or unvaporized fuel is thrown against the heated walls of the 
vaporizing chamber, which are made greatest in area in this region. 
This produces a dry gas and high fuel economy. The gas passes 
around the outside of the plunger chamber, through the main throttle 
valve, and thence goes into the inlet manifold. 

Starting Device. The small pipe shown at 101 is a starting device 
and consists of a pipe connection from the lower part of the float 
chamber into the gas outlet passage above the throttle valve. When 
about to start, the throttle is thrown over to a position in which the 
opening of this pipe is included in the manifold above it. It is then 
susceptible to the partial vacuum existing there, and pure fuel in a 
very fine spray is drawn directly into the manifold. Under normal 
running conditions, its operation is negligible. 

The Dashpot. This device has a solid head to the plunger 69 
and also to the plunger chamber 68 in which it works. Between the 


150 


GASOLINE AUTOMOBILES 


two there is a considerable space, and, as the plunger is a fairly close 
fit in the chamber, this acts as a dashpot and retards the speed of the 
plunger when the motor is accelerating, or when the throttle is opened 
suddenly. By retarding the speed of the plunger, a richer mixture 
is obtained at the precise time when it is needed, in fact, demanded, 
by the motor. And yet when the plunger rises and stops rising, the 
mixture again becomes normal. This arrangement, therefore, does 
not need an extra rich setting in order to obtain good acceleration, 
for the engine can run on a lean mixture with a rapid pick-up. 

Mixture Indicating Pointer. The top of the float chamber carries 
a name plate 88 on which a graduated arc varying from 1 to 9 is 

etched; the 1 end being marked 
poor, and the 9 end rich, as shown 
in Fig. 107. On the top center 
of the float chamber is a regulating 
cap 77 , Fig. 106; attached to the 
top of it is the regulating pointer 
78, which traverses the arc shown 
and in this way indicates the 
quality of the mixture being 
formed with that setting. This 
pointer, shown as straight, but 
having two bends, from a hori¬ 
zontal to a vertical and back to a 
horizontal at the scale, has a small 
hole at one end to which a dashboard controlling lever can be 
attached, thus a quick and easy adjustment can be obtained. This 
pointer, which carries with it the regulating cap 77 , Fig. 106, adjusts 
the degree of vacuum above the gasoline in the float chamber and 
this holds back or partially restrains the flow of fuel to the nozzle. 
When turned to poor, the vacuum is increased, and the flow of fuel 
is reduced, giving a weaker, or leaner, mixture. When turned to rich, 
the vacuum is reduced so the fuel flow is increased and results in a 
richer mixture. This effect is felt throughout the range of throttle 
opening and thus throughout the speed range. It is used also to 
compensate for changes in temperature, altitude, and varying fuel 
densities. This vacuum arrangement replaces the usual change of 
area of the fuel opening in other carburetors. 



Fig. 107. Sketch of Regulating Pointer on 
Newcomb Carburetor 













GASOLINE AUTOMOBILES 


151 


Adjustments. There are but two adjustments: the load- 
carrying adjustment controlled by the pointer 78 and cap 77 just 
described; and the idling adjustment controlled by the regulating 
collar 70, mentioned previously, and shown in Fig. 106. Contrary to 
the usual method, the load-carrying adjustment is made first, and the 
low-speed, or idling, adjustment is made last. To make the load¬ 
carrying adjustment, set the throttle in the special starting position 
as described, turn the regulating pointer to the rich position on the 
dial, then screw the slow-speed ring, or regulating collar, 70 as far up 
as it will go. This is the rich position of the ring for starting only. 
Flood the carburetor by means of the tickler until gasoline appears 
on top of the float chamber. Then start the motor and immediately 
move the throttle to a running position, otherwise the motor will stall. 

With the motor running normally, move the regulating pointer 
78 to about 5 on the dial; this gives an average setting, but different 
points should be tried and the poor-mixture, or lean-mixture, side 
should be favored always. To obtain the best setting, move the 
pointer half a point at a time, and try out the setting each time on 
the road. When the best setting has been found for some one condi¬ 
tion of motor speed and load, the mixture will be found correct under 
all conditions except idling. 

Idling and Low-Speed Adjustment. Now that the load-carry¬ 
ing adjustment has been made, the ring 70 which adjusts the mixture 
for idling should be unscrewed to weaken the mixture until the motor 
throttles evenly, without loading or popping when accelerated. 
Possibly the best combination of slow running and quick smooth 
acceleration may call for a slightly richer mixture than that on which 
the motor idles best and slowest. After this setting has been made, 
to see if the ring is screwed up too far and is giving a richer mixture 
than is necessary, move the regulating pointer 78 slowly from the 
No. 5 point toward poor. If the motor speeds up, the mixture is 
too rich, and the ring 70 should be unscrewed until the motor idles 
correctly with the pointer in the position found to be correct for the 
load-carrying mixture. After the correct idling position has been 
found, all variations for atmosphere, temperature, and fuel conditions 
should be made by changing the pointer only. 

Newcomb Air-heated Model. In addition to Model “B” just 
shown and described, the Newcomb is made in an air-heated form 


152 


GASOLINE AUTOMOBILES 


shown in Fig. 108. This is known as Model “E,” and differs from 
Model “B” mainly in the method of heating (air instead of water), 
the slow speed adjustment, and the arrangement of the high speed 
adjustment. 

In place of the adjusting ring 70 which raises or lowers the 
plunger in Model “B,” spray nozzle is raised or lowered by means 
of an adjusting thumb nut at the .bottom of the carburetor and 
outside. This is seen at the bottom of Fig. 108, which shows 
also how this nozzle would be withdrawn from the metering 
needle or raised to it by such movement. The high speed adjust- 



Fig. 108. Section through Newcomb Model “E” Air-Heated Type Carburetor 
Courtesy Holtzer-Ccibot Electric Company, Boston, .Massachusetts 


ment is much the same in principle, but instead of the pointer on 
top of the float chamber a lever hung in a vertical plane works 
upon a pin “A” between the float chamber and body, this by its 
position governing the amount of vacuum above the fuel, and 
thus, its flow. The starting device is similar to the pipe 101, 
Fig. 100, but the fuel is broken up by the knurled edge of a pul¬ 
verizing ring in the throat above the throttle, the knurling doing 
the actual work of pulverization. 

Marvel Carburetor. The Marvel carburetor, Model “E,” 
shown in section in Fig. 109, is notable for using the exhaust gases 


















































































































GASOLINE AUTOMOBILES 


153 


directly for heating the vaporizing chamber, as well as for pre-heating 
the air used for vaporizing the fuel. The latter is common enough, 
but in the usual case where heating is thought necessary, hot water 
from the motor’s water-circulating system is used. Another novelty 
in this design is the inclined hinged form of air valve set across the 
lower part of the vaporizing chamber. The float chamber A is 
eccentric to the central vaporizing chamber B, but is set very close to 
it, so the ends of the cylindrical float C have to be cut off for clearance. 



Fig. 109. Section through Marvel Carburetor, Model “E” 
Courtesy of Marvel Carburetor Company, Flint, Michigan 


Euel enters from below. It enters the gasoline passage fiom above, 
as this is horizontal. The primary, or low-speed, nozzle I), which is 
adjustable, takes off from this about midway of its length, and the 
high-speed nozzle E from the end. I he former operates within a 
Venturi tube which is supplied with air from below. Above this, the 
chamber broadens out through the zone in which the high-speed nozzle 
contributes, but above that it narrows down again before meeting the 
outlet, the last few inches having exhaust heat applied around it. 









































































































154 


GASOLINE AUTOMOBILES 


These exhaust gases pass downward through an external cylin¬ 
drical passage and, after warming the Venturi and primary nozzle 
region, escape to the atmosphere. This gas is obtained by tapping 
into the exhaust manifold within a few inches of the last cylinder out¬ 
let (4 inches are recommended). As the motor demand rises beyond 
the ability of the primary nozzle, the inclined air valve is drawn 
toward the vertical position, and, as soon as it leaves the cylinder wall, 
the high-speed nozzle is uncovered and starts to contribute. The air 
is supplied from the same air inlet, but it rises more directly. A 
throttle is placed in the air inlet to facilitate starting; closing this 
cuts off the air, so that a richer mixture is supplied. There is a 
damper, or throttle, F in the exhaust gas-inlet passage. It is inter¬ 
connected with the main throttle G in such a way that it is opened 
when the latter is closed and closed when the latter is opened. The 
idea is to furnish a great quantity of heat when the throttle is nearly 
closed, and to gradually diminish the supply as the throttle is 
opened and the motor warms up. 

Adjustments. There are two adjustments: the gasoline adjust¬ 
ment 77, so-called by the maker, and the air adjustment 7. The gaso¬ 
line adjustment operates the primary nozzle. These preliminary 
adjustments can be made on the instrument as received by closing 
the gasoline needle va'lve II by turning it gently to the right until 
seated, then opening it by turning to the left f turn. The air¬ 
adjusting screw I should be turned until the end of the screw is about 
even with the edge of the spring ratchet J provided to hold it when 
set. After starting, close the throttle to produce a moderate speed. 
Then close the gasoline needle II a very little at a time until the motor 
runs smoothly. Allow the motor to get thoroughly warmed up, 
though, before making the final adjustment. 

Next, adjust the air valve. Turn the adjusting screw I to the left 
to back it out and release the air spring about one-eighth of a turn at 
a time until the motor begins to slow down. This indicates that the 
screw is too loose, so turn back slowly, one-eighth of a turn at a time, 
until it runs smoothly again. Next, advance the spark two-thirds of 
its travel and open the throttle quickly. The motor should speed up 
promptly and quickly. If it hesitates or pops back a little more 
gasoline should be released at the needle valve II by turning it to 
the left a very little at a time. It may also be necessary to tighten 



GASOLINE AUTOMOBILES 


155 


the air screw I a little more. Now, wait for the motor to settle down 
to this new adjustment, then open the throttle again quickly. Con¬ 
tinue this sudden throttle opening and subsequent adjustment until 
the point is reached where the motor will respond in a satisfactory 
manner to a sudden throttle opening. The highest economy is 
obtained by turning the air screw to the left and the gasoline needle H 
to the right, closing it as nearly as possible and still obtain the desired 
results. 

Fuel Supply. When the carburetor is fed by gravity, the bottom 
of the bowl should be at least eight inches below the bottom of the 
gasoline tank. When it is fed by pressure, one pound is sufficient, 
and two pounds should never be exceeded. 

The Marvel Carburetor Company also makes a Model “N”, 
designed for Ford cars to which it can be attached without change of 
manifold, levers, or other fittings. It is built on the same general 
plan as the Model “E” previously illustrated and described. 

Schebler Carburetors. The Schebler carburetor is one of the 
simplest complete carburetors made. In general, all Scheblers have 
a concentric float; a single needle valve, the position of which can 
be adjusted to suit varying needs; and an auxiliary air valve which is 
also adjustable. In all these models, too, there is a primary air 
orifice of unvarying section. In the later models, the needle valve, 
or metering pin, as it is more correctly called, is interconnected with 
the air valve so that operation of the latter varies the former. Many 
models are made and all are still in use, but space forbids descrip¬ 
tion of more than four: the widely used “L”; its successor, the 
“R”; and the latest form, the “A,” made with vertical outlet and 
horizontal air inlet, much like the Zenith “L,” which it resembles. 

Adjustment of Model “L.” It will be noted in Model “L,” shown 
in Fig. 110, that the needle valve sets at an angle in the mixing cham¬ 
ber. The upper expansion of this chamber forms the vaporizing 
chamber of long rectangular shape with rounded ends and has the 
auxiliary air valve located at the other end of it. The vaporized 
mixture passes upward, by the throttle, and into the manifold. To 
adjust this model, turn the screw A down to make sure the air valve 
seats firmly, then close the needle valve by turning the adjusting 
screw B to the right until it stops; but do not apply pressure. Then 
turn it to the left four or five complete turns and prime, or flush, the 


150 


GASOLINE AUTOMOBILES 


carburetor by means of the priming lever C, holding this up about 
five seconds. Open the throttle one-third and start the motor, then 
close the throttle slightly and retard the spark. Next, adjust the 
throttle-lever screw F and needle-valve adjusting screw B until the 
motor runs at the desired speed, smoothly and evenly on all cylinders. 
Then make the high-speed adjustment on the dials D and E. Turn 
the pointer on the dial I) from 1 toward 3, about half way. Advance 
the spark and open the throttle so the roller on the track running 
below the dials is in line with the first dial. If the motor back-fires, 
turn the indicator a little more toward 3 , or, if the mixture is too rich, 
turn the indicator back toward 1 until it runs properly. Now open 



Fi^r. IK'. Section through Schebler Carburetor, Model “L” 
Courtesy of Wheeler and Schebler Company, Indianapolis, Indiana 


the throttle wide and make the adjustment on dial E for the high 
speed in the manner just completed on D for intermediate. As lean 
a mixture as the motor will stand is advised. 

This model is also made with a dash-control air valve, as shown 
separately at the left of Fig. 110. Otherwise the carburetor and 
adjustment are exactly the same, except that where the directions 
previously given above have read A , those dealing with the dashboard 
connection should read Ai. As will be noted, the movement of this 
lever rotates a small gear which engages with a rack formed in the air- 
valve stem, so that movement of the lever gives the same result as 
turning the screw A. 





















































































GASOLINE AUTOMOBILES 


157 



Adjustment of Model “R!\ Model “R ”, as Fig. 111. shows, is 
very similar, the most noticeable change being the vertical setting 
of the needle valve (here marked E). Its movement is adjusted by 
an internal lever connected to the air-valve cap A. The air inlet 
group has been raised to correspond with the longer Venturi, and its 
main opening is on top, with the adjusting screw F on the bottom. 
To adjust this model, see that lever B is attached to the steering- 
column control or dash control in such a way that the boss D is 
against the stop C when the lever on the steering column or dash 
registers lean, or air. This is the proper running position. To adjust, 

turn the air-valve cap A 
clockwise, or to the right, 
until it stops, then turn to 
the left, or counter-clock¬ 
wise, one full turn. Open 
the throttle one-eighth to 
one-quarter, start the 
motor, let it warm up, 
then turn the air-valve 
cap A to left, or counter¬ 
clockwise, until the engine 
hits perfectly. Advance 
the spark three-quarters, 
and if the engine back-fires 
on quick acceleration, turn 
the adjusting screw F up 

Fig. 111. Schebler Carburetor, Model “It” Ulltll < CCeleratlOn IS SatlS- 

Courtcsy of If heeler and Schebler, Indianapolis, Indiana factOTV TlllS increases the 

i 

tension on the air-valve spring. Turning the air-valve cap to the right, 
or clockwise, lifts the needle valve E out of the nozzle and enriches 
the mixture. Turning it counter-clockwise lowers it and makes the 
mixture lean. When the motor is cold or the car has been standing, 
move the steering-column or dash-control lever toward the gas, or 
rich, position. This lifts the needle E out of the nozzle and makes a 
rich mixture for starting. As the motor warms up, move the lever 
back toward the air, position to obtain the best running position. 

Adjustments of Mode! “A.” The newest form, Model “A” is 
made in both the vertical and horizontal forms. Only the former 
















































158 


GASOLINE AUTOMOBILES 


will be illustrated here, this being shown in Fig. 112, which pre- 
sents a vertical section. This is built around the principle of the 
“Pitot” tube, utilizing the differential head created by an up¬ 
stream and down-stream pitot tube to control the fuel delivery 
into the Venturi-shaped vaporizing chamber, to which the air has 
access from below. This arrangement gives a fuel flow exactly 
proportioned and controlled by the air. In the figure, E indicates 
the up-stream opening and F the down-stream nozzle of this 
arrangement, with air entering at the lower left through the pas¬ 
sage there, which is controlled by the starting shutter C. The 
high speed adjustment is simple, and is made through the needle 



Fig. 112. Schebler Model “A” Carburetor, a Single Tube Device 
Courtesy Wheeler and Schebler Company, Indianapolis, Indiana 


B. The low speed or idling device delivers fuel and air at the 
low edge of the throttle disc in its closed position, this being 
adjusted through needle A and the passages in the body of the 
carburetor, shown adjacent to A. 

Adjustment of Model “A.” With the lever I) set to give a 
rich mixture, and air choker C set to cut off all the air, both fuel 
nozzles A and B are opened 3 or 4 complete turns from the 
closed or seated position. Open throttle, start motor and let it 
warm up. Then with warming-up lever D fully retarded adjust 
A to correct mixture for idling. Open throttle f and adjust high 
speed mixture with needle B. 

Stewart Carburetor. The predominating feature of the Stewart 
Model “25” is the automatic metering valve by which the air 
admitted measures the gasoline used. This valve, which is the only 
































































GASOLINE AUTOMOBILES 


159 


moving part, is drawn upward by the suction of the motor and comes 

• 

back down onto its seat through its own weight when the suction is 
lessened. In Fig. 113, the complete carburetor with the throttle 
open is shown at the right, and the vaporizing chamber only and with 
throttle closed is shown at the left; the float chamber is the same in 
both cases. Gasoline flows in through the strainer to the float 
chamber, thence to the dashpot, filling this and continuing to rise to 
a point about on a line with the top of the tapered metering pin, 
which corresponds to the usual needle valve. 

With the engine at rest, as shown by the left-hand figure, the 
upper end of the metering valve, which has a conical lower surface. 



■Throttle 


Primary Air Fbssaqes 

Automatic 
'Metering V&lre 


Aspirant Tube 


Dash Pot 


Tapered Meterinq Rn 



Metal float 


Float 

Chamber 


■Inlet Needle 


Gasoline 

Strainer 


Fig. 113. Sections Showing Construction of Stewart Carburetor 
Courtesy of Detroit Lubricator Company, Detroit, Michigan 


rests upon the valve seat, thus closing the main air passage. Its 
lower end extends down into the gasoline in the dashpot. Through its 
center is an opening, known as the aspirating tube, into the lower end 
of which extends (from below) the tapered metering pin. As soon as 
the motor starts, or is turned over, so that a partial vacuum is created 
in the mixing chamber, the metering valve is lilted to admit air past the 
valve seat, as shown in the right-hand part of the figure. This vacuum 
is also communicated to the fuel chamber through the aspirating 
tube, drawing gasoline through it and up the central passage, the latter 
is expanded in diameter near the top and is then flared out to a Luge 
size at the point where the air entering through the vertical holes in 
the metering valve meets the gasoline and picks it up. I lie pui post 



























































































































160 


GASOLINE AUTOMOBILES 


of this flare is to spread the fuel out into a thin film, which the high 
velocity primary air picks up readily in minute particles, producing 
thorough atomization. The high velocity of the air is due to the 
constant vacuum, this vacuum being determined by the weight of the 
valve which is always the same. Obviously, atomization is equally 
good at all speeds. 

Starting. This arrangement also makes for easy starting, but 
this is further facilitated by means of a dash control, which is attached 
to the metering pin in such a way that, when the plunger (on the dash) 

is pulled out, the meter¬ 
ing pin is lowered away 
from the metering valve 
above. This permits 
more gasoline to be 
drawn up through the 
aspirating tube and 
results in a richer mix- 
ture. The dashpot 
arrangement prevents 
rapid fluctuations and 
also makes the metering 
valve slower to respond 
than the fuel valve; in 
this way it produces a 
gasoline lead over the 
air which gives good 
acceleration. 

The higher the 
metering valve lifts in 
response to engine suc¬ 
tion, the greater will be the opening around the metering pin, which 
permits more gasoline to be drawn up; therefore, as the suction 
varies and the metering valve moves up and down, the volume of air 
and amount of gasoline must always increase or decrease in the right 
ratio, automatically giving the right proportions in the mixture at 
all speeds. 

Adjustment. The Stewart has but one adjustment. This 
consists of the lowering or raising of the tapered metering pin, thereby 



Fig. 114. Exterior of Stewart Carburetor, Showing 
Adjustments 

Courtesy of Detroit Lubricator Company, Detroit, Michigan 





GASOLINE AUTOMOBILES 


161 


increasing or decreasing the relative amount of gasoline admitted to 
the mixing chamber in response to the movement of the metering 
valve. This movement is produced by the rotation of the small gear 
A, which engages with a rack on the lower end of the tapered metering 
pin. This gear is rotated by means of a flexible-wire (Bowden) con¬ 
nection to the dash control. The limit of this motion, as well as the 
normal position of the gear, is governed by the setting of the adjusting, 
or stop, screw B, shown in the external view, Fig. 114. 

This screw can be turned either way; turning it to the right 
lowers the position of the metering pin, admitting more gasoline; 
and turning it to the left raises it so that less fuel is admitted. A 
wider range of adjustment than this stop screw affords can be had by 
releasing the clamp C of the pinion-shaft lever 1) and moving it around 
to a new position on the shaft. This adjustment, however, is not 
recommended except for expert repair men. 

With the motor idling the adjustment should be made by moving 
the screw up and down, that is, out and in until the motor runs 
smoothly. This adjustment must be made with the dash control 
pushed all the way in. When this simple adjustment is made cor¬ 
rectly, the device is practically automatic from that time on. A stop 
screw E on the throttle lever is movable and affords the equivalent 
of a limited adjustment, for it can be set to give a smaller and smaller 
opening and thus slower and slower idling. It also has an influence 
on the maximum opening which influences the highest speed. 

Johnson Carburetor. The Johnson carburetor, of which a 
section through Model “D” is shown in Fig. 115, is one of the newer 
designs to be placed on the market. It is a simple form, with a con¬ 
centric type of float chamber A, above which is a simple cylindrical 
mixing chamber B containing the air-regulating device. It is sui- 
rounded by a hot-air jacket C, which warms the mixing chamber and 
furnishes the primary air supply. This is composed of the strangle 
tube I) and air controlling sleeve E, with a lift plate I suspended 

from this sleeve in the strangle tube. 

Operation. Gasoline enters the float chamber from above, in 
the usual way. It enters the spray nozzle through the cioss-hole G, 
then rises inside this and passes the tip of the needle //, where it con¬ 
tinues out through the nozzle point into the lower part of the mixing 
chamber. The fuel issues as a fine spray into the strangle tube D, 


162 


GASOLINE AUTOMOBILES 



which is conical in shape. In the mixing chamber is a sliding brass 
sleeve E, which moves up and down according to the engine suction 
and carries the lift plate F which is just above the outlet from the 
spraying nozzle. Warm air enters the air inlet I and finds its way 

around the chamber 0, some 
of it reaching the passage J 
below the lift plate and stran¬ 
gle tube. Here it picks up the 
fuel from the nozzle and im¬ 
pinges it against the lift plate 
to break it up into finer parti¬ 
cles. In addition, the rising 
air and fuel raise the plate and 
with it the sleeve E, allowing 
more air to enter around the 
bottom of the sleeve. By this 
arrangement, the current of air 
is divided and forms both the 
primary and the auxiliary cur¬ 
rents. The latter current is 
varied to suit the engine de¬ 
mands by the rising and falling 
of the sleeve. This move¬ 
ment of the sleeve automat¬ 
ically proportions the air and 
gas to the demand, for, in 
rising, the lift plate is drawn 
away from the nozzle tip, and 
more fuel is allowed to flow out. 

On top of the strangle 
tube rests a flat choker plate 
K, which is capable of being 
turned around. There are 
holes in this to correspond with the holes in the strangle tube through 
which the primary air passes down to the lower side. In rising again, 
it picks up the fuel spray. A lever L extends through the outside of 
the carburetor and is connected up to the dash control. This lever 
controls the choker plate which can be moved around to cover or 





























































































































GASOLINE AUTOMOBILES 


163 


uncover the air holes and give more or less primary air as the device 
needs it. dhus, the low-speed screw M, the needle valve, and the 
stop screw A on the throttle shaft constitute the adjustments. 

Adjusting the Johnson, the function of the low-speed screw is 
to admit or to cut off the small amount of air supply to the upper 
pa it of the mixing chamber as the motor demands; this screw is to be 
adjusted only with a closed throttle, retarded spark, and the motor 
idling, the motor should be hot. This is an idling adjustment, 
designed to supply additional air through the opening 0, the need for 
which is caused by the sleeve E being in its bottom position and thus 
cutting off the supply, which is available later when the sleeve has 
risen and in so doing has formed the annular air passage. 

The spray needle II, adjusted by the external handle, takes care 
of all other throttle positions and speeds by admitting more or less 
fuel. To adjust it, turn the low-speed screw and spray needle to 
their seats and set the throttle-lever stop screw to approximate the 
correct closed position. Open the spray needle one and one-half 
turns. Start the motor, and when it has warmed up, place the spark 
lever in the fully retarded position; then open the throttle quickly, 
and if the motor does not back-fire, the mixture is slightly rich and 
the spray needle should be closed by turning to the right about one- 
eighth of a turn. Again open the throttle quickly and repeat until the 
motor does back-fire; this will determine a lean mixture. Open the 
needle slightly to correct the mixture, which will give the correct 
adjustment on high and intermediate speed. Adjust the throttle 
stop screw until the desired idling speed, or about 240 r.p.m., is secured. 
If the motor does not fire continuouslv and run smoothlv, the low- 
speed mixture is too rich and is corrected by backing out the low-speed 
screw M until sufficient air is admitted for smooth even firing. Then 
lock it with the lock nut. If this last adjustment has increased the 
speed of the motor, restore the idling speed by unscrewing the throttle 
stop screw N slightly. If necessary, reset the low-speed screw, as 
both of these have to be adjusted in combination. 

Dash Control. This controls the choker plate, which acts as a 
choke to the nozzle by reducing the supply of primary air. After 
the motor has been warmed up, this should be in the wide-open 
position. The position for a cold motor, approximating the closed 
position, will be determined by experience. It is recommended that 


164 


GASOLINE AUTOMOBILES 

> * 

* • 


the motor be choked, that is, the dash control set in the closed position, 
when stopping. This provides a rich charge for starting. As will 
be seen from this, the choker plate, with its dash control, is primarily 
a starting device. 

Other Models. This carburetor is made in other models, notably 
a small one for the Ford car; the essential difference in this being the 
location of the low'-speed screw on t 0 P? as ^ ^ as a horizontal outlet 
on one side and the warm air inlet on the other. Another large size 
for eight-cylinder models has a special accelerating device consisting 
of a fuel plunger operated from the throttle. Still another model is a 



fixed-needle type in which 
the nozzle is calibrated for 
the motor. The adjust¬ 
ment is practically the 
same for all these. 

Carter Carburetor. 
The Carter carburetor is 
a multiple-jet device in 
which, at slow or idling 
speed, but one jet is fur¬ 
nishing fuel, while at ex¬ 
treme high speed eighteen 
are operating. These are 
not jets in the sense that 
the ordinary carburetor 
has separate vertical or 
horizontal jets, as in the 
Master carburetor, for 
instance, but they consist of a series of holes set spirally around a 
central standpipe of fairly large diameter. The action of the device 
is such that only one is working at low speed, while at high speed 
the great suction is drawing the fuel up so high in the standpipe that 
it is issuing from the entire group of 18 holes. 

A vertical section through the center of this carburetor is shown 
in Fig. 116. As will be noted, the bottom of this rests in a tube, or 
open standpipe, which communicates with the float chamber and is 
kept filled to the float level with fuel. Just at the top of this tube is 
the main air inlet. The air enters around the sides of the standpipe 


Fig. 116. Section of Carter Multiple-Jet Carburetor 

Courtesy of Carter Carburetor Company, 

St. Louis, Missouri 












GASOLINE AUTOMOBILES 


165 


and rises vertically along it. Around the upper part of the standpipe 
is a flaring conical tube, the top of which is closed by a damper. Air 
enters here and is drawn downward, its amount being controlled by the 
damper. At the left will be seen the supplementary air valve, a third 
source of air; this air is also drawn downward, and the amount is 
adjustable. I 1 rom this it can be seen that the primary air and the fuel 
from the first few jets come upward, while the secondary air and the fuel 
from the additional jets go downward, and that the supplementary air 
rushes in at an angle where these two meet at the bottom of the 
U-shaped vaporizing chamber. This produces a constant state of 
turbulence around the standpipe, which facilitates breaking up and 
vaporizing the fuel. The fuel passes a butterfly throttle in its 
passage to the inlet manifold. 

For easy starting, a tube (marked anti-strangling tube in the cut) 
is by-passed around the vaporizing chamber, taking its fuel directly 
from the well at the left of the float chamber and furnishing it 
directly into the outlet pipe above the throttle. In starting and 
idling on the lowest jet, or hole, of the standpipe, the fuel is drawn 
almost directly from the float chamber. For this reason an unusually 
accurate float arrangement is necessary, and this is provided by the 
metal ball float and the needle arrangement with its ball and spring 
shock absorber. The latter eliminates any possibility of jamming 
and gives accurate control of the fuel level. The action of the device 
is very simple, the engine suction drawing the fuel higher and higher 
in the standpipe as the suction increases, while the same suction draws 
open the intermediate air valve as soon as the required supply exceeds 
the capacity of the main air intake. The high-speed air inlet, oper¬ 
ated by the damper, is thrown into action from the steering post or 
dash at the will of the operator. 

Adjusting the Carter. By reference to Fig. 116, the adjust¬ 
ing will be made plain. First set the high-speed adjustment with the 
lever in a vertical position; then turn the knurled button marked low- 
speed adjustment down, or to the right as far as it will go; next back 
it off and turn it to the left three-quarters of a turn. Turn the 
knurled valve ring marked intermediate-speed adjustment to the 
point where the valve seats lightly, then turn the valve down, or 
to the right, from eight to ten notches to increase the spring tension. 
Full the easy-starting lever, connected with the dash, forward to 


160 


GASOLINE AUTOMOBILES 


the position shown in Fig. 119, advance the spark a very little, 
close the throttle, and start the engine. 

Through the medium of the anti-strangling tube, this will 
furnish rich mixture (almost pure fuel) to the inlet manifold and 
result in instantaneous starting. Immediately reverse the easy- 
starting lever which controls the flow of fuel and open the main 
throttle slightly. By means of the two screws A A on either side 
of the throttle lever, set the throttle valve where it gives the 
desired engine speed when idling. Move the low-speed adjust¬ 
ment to the left, one notch at a time, until the engine slows 
down, noting each setting. Now move it in the opposite direc¬ 
tion, one notch at a time, until the engine again slows down. 
Then move the adjustment to a point midway between the two, 
and the low-speed setting will have been finally fixed. This 
should not be changed on account of weather or temperature 
variations. 

Set the throttle about one-third open and turn the inter¬ 
mediate adjustment to the left until the engine slows down. 
Move to the right until a similar decrease in speed is noted, then 
set midway between the two. This adjustment, when once 
properly made, should not be changed for weather or temperature 
changes. After this adjustment has been made, connect the high¬ 
speed adjusting lever to the dash or steering-post control so that 
in the center of its movement the lever on the carburetor is verti¬ 
cal. Drive the car over a level road at about 20 miles an hour, 
then move the control lever to the point where the engine gives 
the best results at this speed. At low temperatures, or when the 
engine is cold, this control should be moved toward the closed 
position, so as to cut off air and make a richer mixture. At high 
temperatures and with a warm engine, the best results are obtained 
with the control wide open. This is the only adjustment which 
should be varied for weather or temperature variations. 

Newer Carter Models. In addition, this company has two 
newer models, “H” and “L,” the principal difference being in the 
outlets, “H” having a vertical and “L” a horizontal outlet. The 
former is shown in Fig. 117, which shows both a vertical section 
and end view. It will be noted that the fuel passes through a 
strainer into the float chamber, then entering below passes through 


GASOLINE AUTOMOBILES 


167 


the high speed jet if the throttle is open and through the small 
hole in it, and thence through the low speed jet, up the vertical 
fuel passage, and part passes out into the vaporizing chamber, 
while part continues on up into the inlet manifold above or beyond 
the throttle. The action of these two jets is evident from their 
construction and this description. 

Adjustment of Carter “II" and, “L ” Models. The adjustment 
of these two models is similar, this being controlled ordinarily by 
setting the throw of the throttle lever in the proper position for 
idle engine speed. This is done by means of an adjusting screw, 



Fig. 117. Carter Model “II” Carburetor with Vertical Outlet 
Courtesy Carter Carburetor Company, St. Louis, Missouri 


which is provided with a lock screw to hold it when adjusted. 
This lever should be so set that with steering wheel quadrant 
lever and accelerator closed, engine will turn over at normal idling 
speed of 250 to 300 r.p.m. Model “L” has an additional idling 
adjustment, consisting of a small screw which controls the amount 
of fuel passing out into the manifold beyond the throttle. The 
only other normal adjustment is the connection of the dash 
control wire to the carburetor choker lever; shortening this will 
cause the air shutter to close more tightly, lengthening it, not as 

tightly. 

H. & N. Carburetor. This device, shown in Fig. 118, uses 
no springs, yet two adjustments are provided. Fuel enters from 



































































































168 


GASOLINE AUTOMOBILES 


below, into a nozzle, the metering needle projecting down into 
this, somewhat the same as in the Newcomb previously described. 
This needle is incorporated in or carried by a movable air valve, 
which is gradually raised permitting more air to enter as the 
engine speeds up and the suction becomes greater. In its lowest 
position, it governs the amount of air entering at idling or low 
speeds, and this low position is'adjusted by raising or lowering a 
threaded ring upon which it seats. It is fitted into the body of 
the device in such a way that an air chamber is left above it, 
between its upper surface and the body. This enclosed air 
chamber is fitted with a vacuum relief valve, which constitutes the 



high speed adjustment. Opening the relief valve permits the air 

valve to rise higher at high 
motor speeds, and this higher 
valve position admits more 
fuel through the fuel nozzle, 
and more air through the 
auxiliary air ports which it 
uncovers. Thus, the device is 
wholly automatic in its action. 

Adjustment of the H. & N. 
These two adjustments are 
utilized in the normal way. 
The engine is started and 
heated up, then the low speed 
adjustment is operated through its milled outer edge, until the 
idling and low speed performance is satisfactory. The engine is- 
then speeded up, and the high speed adjustment varied to pro¬ 
duce maximum speed and power. 

Tillotson Carburetor. In a general way the Tillotson car¬ 
buretor resembles a long U-shaped tube laid upon its side, with 
the air entering the upper branch, passing around the curve and 
out to the motor at the end of the lower branch. In the latter 
near the delivery end, are placed the two jets, first the secondary, 
next the primary. A pair of flexible reeds are arranged within 
the passage in such a way that they entirely enclose and shut off 
the secondary when they are closed, but do not interfere with the 
primary. The reeds are opened by the suction of the engine, so 


Fig. 118. Section Showing Simplicity of 
H. and N. Carburetor 

Courtesy H. and N. Carburetor''Company, Long 
Island City, New York 











































GASOLINE AUTOMOBILES 


169 


that the primary nozzle furnishes fuel at all engine speeds but is 
the only one in operation at the slower speeds, and is the only one 
that is adjustable. The secondary nozzle gives the added fuel for 
high engine speeds and is in operation at these higher speeds only. 

Not all the Tillotson models have this exact shape, many 
being more of an L shape. The float chamber location varies 
with the different models in some being below the I (or L) tube, 
in others at one side. 

Adjustment of the Tillotson Carburetor. As has been stated the 
primary nozzle only is adjustable. The company recommends 
that this be done with unusual care, and very slowly. With the 
motor running and well warmed up, turn the adjusting handle up 




Fig. 119. Tillotson Model “C” Carburetor, Showing Steel Reeds 
Courtesy Tillotson Manufacturing Company, Toledo, Ohio 


to the right until the motor commences to slow down from lack of 
fuel, then turn it back about one-eighth of a turn. Avoid getting 
the mixture too rich. Fig. 119 shows Model ( ’ 85-6 impartial 
section and the reed action. 

Knox “F” Carburetor. In the Knox carburetor, made by the 
Camden Anchor-Rockland Machine Co., the automizing valve 
takes the form of the usual mushroom or poppet valve of engines, 
the stem being drilled out and the atomizing openings being 
drilled radially and horizontally into the mushroom or upper part 
of this. This gives a radial series of sprays of fuel into the 
enlarged mixing chamber, which is heated externally by warm air, 
and receives its air from below through a large opening. The 
combination of this widely diffused spray, the large air opening 


































































170 


(;ASOLINE AUT( )M()BILES 


with the air entering at the widest extremity of this spray and the 
heating should make for complete vaporization. The device is 
shown in section in Fig. 120. 

Adjusting the Knox. The setting of the choke valve can be 
varied slightly with some effect on the running of the motor, but 
the only real adjustment is that of the needle valve, (’losing the 
choke valve cuts down the air and produces a richer mixture. 
When three-fourths to fully closed, it primes the motor through 
the priming tube, and should be closed only on starting for this 
reason. The metering needle regulates the flow of fuel as the 
atomizer rises and falls. Before the carburetor is attached, this 
should be screwed up until it lifts the atomizer off its seat. Then 



Fig. 120. Section through Knox Model “F” Carburetor 
Courtesy Camden Anchor—Rockland Machine Company, Camden, Blaine 

it should be unscrewed three or four full turns to give a starting 
setting. Put the carburetor on the motor, start it and run until 
warm, then adjust working the choke valve up to full opening and 
the throttle down to lowest idling speed, until the motor runs 
smooth and right. This done, open the throttle and try the run¬ 
ning at full throttle. If properly adjusted and the motor does not 
pick up and show more power, a larger needle must be inserted, 
and if the motor acts starved, insert a smaller needle. 

Sunderman “Nitro” Carburetor. In the Sunderman “Nitro” 
carburetor a mushroom jet and an air bypass are used in con¬ 
junction with a floating Venturi to attain the desired vaporization 
results. This is shown in Fig. 121, which indicates a section 











GA$( )LINE AUTOMOBILES 


171 


through this simple carburetor at high, medium and low speeds, 
these illustrations make the construction, and other details self- 
evident. 

Adjusting the A itro. There is but one adjustment provided, 
modification of the suction on the jet by a screw which governs 





High SSp&ed 


fizd/L/m Speed 




Fig. 121. Sketches Showing Operation of Venturi in Sunderman Xitro Carburetor 
Courtesy Sunderman Corporation, Newburgh, New York 


the size of the air passage where it makes the right angle bend. 
This adjustment reduces the suction of the nozzle at lower speeds 
and thus, the flow of fuel, and prevents the Venturi rising too 
rapidly. Thus, it is ad¬ 
justed only for idling and 
slow speeds. 

Shakespeare C a r = 
buretor. The feature of 
the Shakespeare carbu¬ 
retor, shown in section in 
Fig. 122, is the automatic 
valve which forces a pos¬ 
itive mechanical subdi¬ 
vision of the fuel and 
simultaneous mixing of 
the air at a low vacuum. 

As will be noted in the cut, this is accomplished by giving the fuel an 
outward flow, much the same as the mushroom drilled valve of the 
Knox or the Xitro, air being led into the center of this and 
around the outside at the same time. 


Muring Cham! 


Automatic 

High Speed Valve 

Law Speed Adjustment 


Carbureting Chamber 
and Muring Chamber 


fleunbie Hose to 
Hot Air Steve 


Dash or 
Steering 
Column 



Air Intake 
rimer and Tem.jercture Control 

Dram 


Fig. 122. Section through Shakespeare Carburetor 
Courtesy Shakespeare Company, Kalamazoo, Michigan 






. t ft 1 
















































172 


GASOLINE AUTOMOBILES 


Adjusting the Shakespeare. The makers call this a one-adjust¬ 
ment model, the nozzle being adjustable toward or away from the 
needle, and this constituting the low speed adjustment, which is manip¬ 
ulated in the usual way. There is, however, a high speed air valve 
for the extremely high or racing speeds, and this also is adjustable. 

Packard Carburetor. The carburetor used on the Packard 
twin-six (twelve-cylinder) cars is shown in section in Fig. 123. The 
inlet manifold, or rather the pipe which leads in both directions to the 



Fig. 123. Section through Packard Twin-Six Carburetor 
Courtesy of Packard Motor Car Company, Detroit, Michigan 


manifold proper, is seen at the top at A. It will be noted that this is 
water-jacketed, the water space being at the top. The float arrange¬ 
ment is of the usual type, with a metal float which supplies fuel to a 
small well B at the base of the single-spray tube C. This has a flared 
end located in the center of the Venturi. When the air from the air 
horn D passes the air shutter E, it picks up the fuel and carries it up 
into the vaporizing chamber F. The primary air shutter is normally 
open but not in use. It is operated by a hand wheel on the control 
board which also operates the auxiliary air valve G. By turning this 

















GASOLINE AUTOMOBILES 


173 


clear over to the position marked choke, the air intake is closed, and a 
rich mixture is drawn in for starting. After that, the hand wheel 
should be set back toward the position marked air which opens the 
air intake. 

The auxiliary air valve is controlled by the springs II and 1. 
These are adjusted so that the valve opens very slightly at low speed, 
but more and more as the speed, and consequently the suction, 
increases. The air enters around the outside of the Venturi, communi¬ 
cating with the mixture only above the top of the latter where the 
real vaporizing chamber commences. The tension of the springs is 
varied by means of the adjusting nuts at the top and by the adjusting 
cams J. The cams are connected up to the air-valve hand wheel which 
is turned toward gas to provide a richer mixture and toward air for a 
leaner mixture. If the wheel is turned too far toward air, spitting 
back may result ; and if it is turned too far toward gas, the result may 
be irregular running and overheating. The throttle K is of the but¬ 
terfly type and regulates the quantity of mixture allowed to pass out, 
not its quality. An adjustable stop holds this valve open slightly 
and allows a small amount of mixture to pass, even when the hand 
throttle is entirely closed. This minimum amount is for slowest 
running, or idling, only. To increase it, loosen the check nut L and 
screw the stop M forward. To decrease the minimum speed, screw 
the stop backward. 

Adjustments. Aside from those described previously, the 
Packard Company advises against making any adjustments as it 
prefers to have this done by its own men, who have had extended 
experience in adjusting the motor and carburetor combinations. 

Cadillac Carburetor. A section through the latest Cadillac 
carburetor, which is a very simple device, is shown in Fig. 124. Fuel 
enters through the pipe A at the bottom, passing on to the well B, 
and thence to the float chamber, through the vertical pipe C and the 
float valve D, which are operated by the float E. This float is con¬ 
centric and is hinged on one side of the float chamber. Below the 
float chamber is another chamber, or well, F which is supplied from it. 
Through the opening in the side of the nozzle G, this well in turn sup¬ 
plies fuel to the nozzle II, the fuel being drawn out at the top into 
the Venturi chamber I. At the left will be seen the air valve J as well 
as the scoop of shield K, which assists in drawing in the required 


174 


GASOLINE AUTOMOBILES 


volume of air. This air reaches the passage L, whence a portion is 
drawn downward around the outside of the A enturi /, through the 
passage M, and around the bottom of the tube, then upward. 1 here 
it mixes with the fuel spray, vaporizes it, and carries it up into the 
main vaporizing chamber N, where additional air comes in from L, 



Fig. 124. Section through Cadillac Carburetor Used on Models 53, 55 and 57 
Courtesy of Cadillac Motor Car Company. Detroit, Michigan 


and the mixture passes on up, through the throttle valve 0, into the 
inlet manifold. 

On a lever P attached to the throttle valve shaft is hung the 
cbnnecting rod Q, by means of which it is attached at its lower end to 
the piston R. This works up and down in the chamber S. Its lower 
portion, or well, T is full of fuel and communicates through passage U 
with the well F and the nozzle II. When the throttle is opened, the 
plunger is forced into the gasoline in the carburetor bowl, and fuel 
is thus forced through the hole G up to the nozzle II. When the 




















GASOLINE AUTOMOBILES 175 

throttle is opened quickly, this acts to supply the needed fuel. When 
the throttle is opened slowly, the plunger has practically no effect. 
Lhis plunger has an influence on starting, as will be explained. 

Adjustments. Carburetors are factory set and should need no 
adjustment ordinarily, but for different atmospheric conditions a 
slight change in the air-valve spring may be needed. In the exterior 
view, big. 125, this is altered by turning the screw V. In case the 
carburetor really needs adjustment, proceed as follows: Open the 
throttle lever on the steering wheel about two inches, place the spark 
in the driving range and start the motor; run it until the water jacket 


Fig. 125. Exterior View of Cadillac Carburetor, Showing Adjustments 

on the intake pipe is hot; then move the spark lever to the extreme left 
on the sector and the throttle lever to a position which leaves the 
throttle slightly open, and adjust the air-valve screw V to a point 
which produces the highest engine speed. Turning this screw clock¬ 
wise increases the proportion of gasoline to air in the mixture, that is, 
makes it richer; while turning it counter-clockwise decreases the 
proportion of gasoline, that is, makes it leaner. 

Close the throttle by moving it to the extreme left on the sector, 
and adjust the throttle stop screw W to a point which causes the 
engine to run at a speed of about 300 r.p.m. The spark lever should 








176 


GASOLINE AUTOMOBILES 


be at the extreme left when this adjustment is made. With the spark 
and throttle levers in this same position, adjust the air valve screw I 
again to the highest motor speed. Open the throttle until the shutter 
attached to the right-hand end of the throttle shaft just covers the slot 
in the carburetor body (the other side of the carburetor is not shown 
in either view). Then adjust the screw X to the point which pro¬ 
duces the highest engine speed or to a point where the engine slows 
down slightly from a lean mixture. This screw also works clockwise 
to give a richer mixture and counter-clockwise for a leaner one. 
During very cold weather, it will be found advisable to turn this screw 
farther in a clockwise direction to give a slightly richer mixture. 

The rod Q from throttle arm P to the fuel plunger is adjusted 
closely at the factory and should need no change unless the carbu¬ 
retor is disassembled. When reassembling, the rod should be ad¬ 
justed so that its upper end is flush with the upper face of the arm P. 
When the carburetor has been used for a long time, there may be slight 
wear at the point of the inlet or where the float needle D, Fig. 121, 
rests on its seat. If this should occur, the height of the fuel in the 
carburetor bowl will rise. To determine whether the float is set 
properly, remove the carburetor from the engine and the bowl from 
the carburetor. Then measure the distance from the upper surface 
of the float to the metal surface above it, as indicated at Y to Z. 
This is measured best with the carburetor inverted and should be 
exactly \ inch. If more, or less, the setting may be corrected by 
slightly bending the arm to which the float is attached. 

Starting. In cold weather, when the engine will not start imme¬ 
diately, it is not advisable to continue cranking the engine over and 
over. Instead, open and close the throttle rather quickly once or 
twice, no more, with the throttle lever on the steering wheel or foot 
accelerator. This action raises and lowers the throttle pump at¬ 
tached to the throttle-shaft arm, as previously explained, thus raising 
the level of the fuel in the float chamber so that it is more easily 
drawn up. If pumped more than once or twice, too much fuel will 
be forced up, and this is just as bad as too little. 

Oxygen=Adding Devices. There are now upon the market a 
number of devices for assisting carburetion by furnishing an 
additional source of oxygen. These are not carburetors in them¬ 
selves, in that they do not handle any fuel, consequently they 


GASOLINE AUTOMOBILES 


177 


must be used in addition to some standard carburetor, furnished 
with fuel in the regular way. The desired result is obtained in a 
number of different ways, as for instance the direct injection of 
water, which the heat of combustion is supposed to break up into 
its components hydrogen and oxygen. The hydrogen is a fuel 
itself, and the oxygen assists the vaporized gasoline fuel to burn 
better and more completely. Steam is but a variation of this, 
the exhaust heat being used to create this from water furnished 
by a special tank. When equipped with valves to control water 
passage or steam emission, these constitute the only adjustment. 

KEROSENE AND HEAVY FUEL CARBURETORS 

Need for Heavy Fuel Carburetors. As has been mentioned 
several times previously, and explained elsewhere in detail, the 
lighter, more volatile grades of gaso¬ 
line are not available in sufficient 
quantities to supply the present de¬ 
mand. Consequently, the fuel now 
carries a considerable quantity of what 
was formerly sold as kerosene and also 
under other names. At that, the fuel 
sold is still much lighter than kero¬ 
sene—of which tremendous quantities 
are available—as well as other heavy 
fuels, notably benzol in England, where 
kerosene is called paraffin. To de¬ 
velop a carburetor which would handle 
these cheaper but heavier and more 
available fuels has been the aim of 
many inventors and a vexing problem 
for carburetor manufacturers. 

Holley Type. A firm, the Holley 
Company, which has devoted much time and study to this problem, 
has developed the device shown in Fig. 125. While this is not 
offered as perfect, even by its maker, who is still working on this 
problem, it has been found to do these things: cut the fuel cost 
over 50 per cent; increase the power 5 to N per cent; sa\e almost 
one-half of the engine lubricant; give less spark-plug trouble and 



Fig. 126. Section through the Holley 
Kerosene Carburetor 






































































178 


GASOLINE AUTOMOBILES 


less carbonizing; and give a greater mileage to the gallon. It 
also has these deficiencies: requires the use of gasoline for starting; 
and necessitates a material reduction in compression pressures. 

This device as shown in Fig. 126 has two float chambers, one 
for gasoline used in starting, the other for the kerosene or heavier 
fuel. The shifter valve B determines which fuel flows to the 
adjusting needle valve W and through a jet where a minute 
quantity of the total air needed in the form of an air blast 
atomizes it. Then it is carried up through the tube R situated in 
the exhaust manifold and heated by it. Then it enters the main 
mixing chamber M, where the main air supply enters through U, 
this opening being governed by the suction of the motor and the 
throttle valve opening. From here it is drawn in through the 
intake manifold V in the usual way. 


Adjustment Holley Kerosene Device. In general, the motor is 
always started on gasoline, which is used purely for starting and 
warming up the motor, when the change over to kerosene is made. 
The adjustments should be made on the basis of kerosene, even 
though it seems somewhat rich when running on gasoline. Set screw 
E, which limits the throw of the throttle lever, should be adjusted 
so the motor runs at proper idling speed when the hand throttle 
lever is in the closed position. 

Holley AlUFuel Carburetor. Another Holley device is intended 
for the use of all kinds of fuel, heavier than our so-called gasoline. 
This is shown in Fig. 127, which presents a sectional view and 
explains all the parts as well as the operation. It consists of a 
simple spraying device with an air valve which sprays the heavy 
fuel, adds a very small amount of air to it, and then forces this 
mixture through a vapor tube, consisting of coils of thin-walled 
pipe surrounding the exhaust pipe. The exhaust heats the walls 
enough to completely vaporize any fuel that will evaporate below 
600° F. This heater, rich, dry gas mixture is then returned 
to the main body of the carburetor where additional cold air is 
admitted to convert it into a perfectly combustible mixture. It 
then passes through the throttle and inlet manifold to the engine. 
Like the Holley kerosene carburetor just described, this starts on 
gasoline, and is switched to the heavier fuel as soon as the motor 
is well warmed up and the exhaust heat begins to be available. 


GASOLINE AUTOMOBILES 


179 


Aside from the usual throttle and air valve limit stops, there 
really is but one adjustment. 

Adjusting the All-Fuel Carburetor. The principal adjustment 
on this device is the idling. The figure shows this near the bot¬ 
tom, it consisting of a valve with a milled outside head which 
controls the inflow of air. Sufficient air is drawn past this for 
idling and it lifts to admit more air for higher motor speeds. 
1 he valve is regulated so that in its lowest position just enough 
air passes to give a satisfactory idling speed. An arrow on the 



Fig. 127. Section Showing Construction of All-Fuel Carburetor 
Courtesy Holley Brothers Company, Detroit, Michigan 


top indicates this. When the valve is entirely closed, as indicated 
by the arrow, the air is practically shut off" and the mixture is richest. 

The air intake is fitted with a choke throttle and the tight¬ 
ness of closing this can be regulated by a stop screw. Similarly, 
the main throttle can be regulated by means of a stop screw, to 
va'y its tightness in the closed position. The only other changes 
or adjustments would be to change the atomizer for one with differ¬ 
ent sized jet holes at Y and X as well as the primary air inlet. 

Foreign Kerosene Carburetors. A large number of firms in 
different parts of the world have worked on this problem of kerosene 
vaporization. In Germany, the following have done so, and in 













180 


GASOLINE AUTOMOBILES 


solving this each has been obliged to develop his own vaporizer: 
Daimler; Swiderski; Maurer; Adler; Sleipner (boats mostly); Deutz; 
Banki; Neckarsulmer (motorcycle); Koerting (fuel injection); Kam- 
per; Diesel (fuel injection); Capitaine (boats mostly); Gardner; 
Dufaux (Swiss motorcycle); and others. Space prevents a descrip¬ 
tion of these, the list being given simply to show that kerosene as a 
fuel has attracted wide attention. 

In France the same is true; the Aster device, for instance, having 
been so very successful that it is now made under license in both 
England and Germany. 

In England the Binks, with two jets, is designed to use 20 per 
cent gasoline and 80 per cent kerosene after starting. The Hamilton 
Bi-fuel has two float chambers, two nozzles, and other duplicate 
features. This is designed for a 44 gasoline (petrol) and 56 kerosene 
(paraffin) mixture; on such a mixture, a test of a bus engine showed 
equal (rated) power at 890 r.p.m.; 1 horsepower more at 1050; almost 
3 more at 1275 ; and at its highest speed 1375 r.p.m., 3 horsepower more, 
maximum output. The Kellaway has two fuel leads, but these use a 
common jet. The Morris uses forced feed with a constant air pressure 
of 4 pounds per square inch on the fuel tank; this is supposed to mini¬ 
mize variations in fuel flow, and thus, as pointed out in the description 
of the Browne, minimize variations in the output. The Southey 
ignites part of the fuel to create heat with which to vaporize the bal¬ 
ance, delivering to the cylinders a fixed gas which is heated. The 
Edwards has been described. In the Notax the fuel spray, as it 
enters the vaporizing chamber, is forced to strike the lower hot surface 
of the exhaust-gas passage, which not only encircles the chamber but 
has a passage right through the middle of it. In the G. C. (English 
and American), the vaporizer complete replaces both carburetor and 
muffler. It is constructed to utilize all the heat in the exhaust gases 
for vaporizing the kerosene, which then is led up to the engine, and 
auxiliary air added just before it enters the manifold. This has a 
separate small gasoline carburetor for starting and a special float 
chamber for the kerosene. In America, the Knox employs an 
arrangement in which a gasoline by-pass around the entire carburetor 
is used for starting, while the exhaust heating concerns the fuel at the 
bottom of the device only. The Secor type is used on the Rumely 
tractors. The Hart-Parr Tractor Company and a number of other 


GASOLINE AUTOMOBILES 


181 


builders of ti act or, marine, and stationary engines have been more or 
less successful in vaporizing kerosene so as to use it advantageously. 

Master Carburetor. T he Master device, previously shown 
and described, was designed primarily for the extra heavy fuels, or 
the residuum in the distilling process called distillate, which is 
heav ier than kerosene and has heretofore been considered a waste 
product, d he Master has utilized this successfully in actual serv¬ 
ice for more than four years. In addition, it will handle kerosene, 
alcohol, and other heavy fuels, as well as mixtures of all these 
with one another and with gasoline. 

Like the Master, the Miller also previously described as a 
gasoline device, was designed originally for the extra heavy fuels 
of the coast, so that it must be considered as a heavy fuel car¬ 
buretor. This is partly true of the “H and N,” which was 
designed originally for heavy fuels, the present form embodying 
the most successful details of the heavy-fuel device. 

Bennett Carburetor. The Bennett device, Type “C” which 
is shown in section in Fig. 128, is intended for kerosene, alcohol, 
distillates, or other heavy fuels, but by a simple change of the 
adjustments it can be used for gasoline. For alcohol, however, the 
makers provide a special float, the carburetor remaining the same 
otherwise. It has two needle valves: one projecting downward 
from the top of the device A, called the slow-speed needle; and the 
other, projecting upward from the bottom B, called the high-speed 
needle. The primary air for both enters at C, passes around the 
exhaust heating pipe I), and enters from below. It rises around 
the lower needle and fuel passage into the chamber E, where the 
fuel is picked up and carried up into the main vaporizing ehamber 
F. From here it passes up into the passage G, where additional 
air comes in from the air valve II, after passing the air throttle I. 
This dilutes the mixture and completes vaporization, and the mix¬ 
ture passes the main throttle J into the manifold, or engine. 

The fuel enters the float chamber K, in which the float is indi¬ 
cated, and passes from this through the horizontal opening L to the 
needles. As there is hot air in the passage just below the opening, 
and exhaust gases in the passage just above it, it is subjected to a 
considerable warming effect. In the center at the bottom, a recess 
forms a dashpot for the lower end of the shaft M, which is connected 


182 


GASOLINE AUT()MOBILES 


to the air valve II at its upper end; this prevents rapid fluctuation, 
or fluttering, of this valve when there is a sudden opening of the 
throttle after running at slow speed. The extra suction created by 
the sudden opening# of the throttle tends to jerk the auxiliary air 



Fig. 128. Section through Bennett Double-Jet Kerosene Carburetor 
Courtesy of Wile ox-Bennett Carburetor Company, 
Minneapolis, Minnesota 


valve open quickly to its maximum area. Another feature of the 
device is the feeding of small quantities of hot water from the motor 
circulating system through the pipe N; this has an adjustable valve 
(not shown) connected to the dash. The water is sprayed in through 































































































































































































































GASOLINE AUTOMOBILES 


183 


the medium of the valve 0 attached to the bottom of the small dash- 
pot and the plunger P which surrounds the bottom of the high-speed 
needle B . An additional feature of the device is an air cleaner Q, 
which is shown at the left in the diagram, Fig. 129. Its function 
is to clean all dust out of the entering air when the carburetor is 
used on a tractor or other unit which must work in the midst of con¬ 
siderable dust. As this dust is known to filter slowly but surely 
thiough the carburetor and, in time, reach the pistons, valves, rings, 
and bearings, where it does considerable damage, the utility of this 
simple auxiliary device, which has no moving parts, is evident. 

Installation. Whenever it is possible to use the air cleaner, 
install the carburetor with the hood of the air intake facing away from 



Fig. 129. Diagram Showing Method of Connecting and Adjusting Bennett Carburetor 


the fan so as to prevent dirt from being blown into it. Connect the 
exhaust manifold to the carburetor, using the three-way valve or 
damper in such a way that the amount of gas can be regulated. When¬ 
ever possible the exhaust connection should enter the larger end, 
because the cored passage for heating the primary air is there. Screw 
an elbow in at the other end, and, if required, a short piece of pipe, 
to carry the used exhaust gases away from the carburetor. Connect 
the water jet near the bottom with the water jacket or a small 
auxiliary water tank. This water jet and its regulating needle can be 
moved to any desired position by means of the large nut R. The 
needle is connected to the dash so as to be operated by the driver. 
Two fuel tanks are needed, one for gasoline to be used for starting, 












































































































































184 


GASOLINE AUTOMOBILES 


and the other for kerosene to be used in regular running; they should 
be connected to the float chamber at the bottom by means of a three- 
way valve or a siamesed pipe, with a shut-off cock in each line above 
the T-connection. 

Adjustment. There are but two adjustments, so-called: the 
high-speed fuel needle for full load; and the slow-speed fuel needle for 
slow T speeds and idling. Both are made by knurled nuts, which are 
turned clockwise to close and counter-clockwise to open. In the 
process of adjusting, close the exhaust damper S, so as to throw the 
exhaust gases through the carburetor and furnish the needed heat. 
Then close the air-choke valve I, to make a rich mixture for starting 
purposes. Before turning on the gasoline, open the high-speed needle 
B about two turns. Then start the motor and immediately open the 
air choke valve I. If it fires unevenly after running a little while, 
close the slow-speed needle A by turning the knurled nut T to the 
right, one notch at a time, until the motor fires and runs evenly when 
throttled down to the slowest speed. If the motor hesitates and stops 
when the air choke valve is opened, open the slow-speed adjustment, 

one notch at a time, until the point is reached at which the motor 

< 

will just run and fire evenly when throttled down. 

Regulate the high-speed needle until the motor will respond when 
the throttle is opened quickly, by speeding it up to its maximum 
number of revolutions without missing. If the motor misses when 
the throttle is jerked open, close the needle slowly, one notch at a 
time, until the missing ceases and the motor responds to the quick 
opening smoothly. On the other hand, if the motor back-fires when 
the throttle is suddenly opened wide, open the needle slowly until it 
will speed up without missing or popping back. As soon as motor and 
carburetor have become thoroughly heated, turn on the kerosene 
and shut off the gasoline. 

Kerosene Modified Adjustments . The use of the kerosene may 
change the adjustments slightly. Thus the slow-speed needle adjust¬ 
ment may have to be opened one or two notches more for kerosene 
than for gasoline. Similarly, the high-speed needle adjustment will 
have to be opened two or three notches more. If the motor becomes 
so hot when running on kerosene that pre-ignition occurs—and this is 
likely because the whole device is designed to use the maximum pos¬ 
sible amount of heat—the water-needle connection to the operator 


GASOLINE AUTOMOBILES 


185 


should be opened. This pre¬ 
ignition can be detected as 
a sharp metallic knock in 
the cylinder. Only enough 
water should be used to stop 
the knock; the carburetor 
should not be flooded with 
it. The cap at the bottom, 
or inlet, of the air cleaner 
Q should be kept tight. The 
air cleaner should be emp¬ 
tied once aday, but it should 
•not be removed while the 
engine is tunning. 

Bennett Air Washer. 
The wider use of tractors 
and also of cars and trucks 
in the country, over dusty 
roads, and in the dust-laden 
fields which are being 
plowed, harrowed or other¬ 
wise worked, has forced the 
use of devices for removing 
the dust from the entering 
air. The device indicated 
at Q is one of these and is 
shown in detail in Fig. 130. 
Its interior consists of a 
series of spiral passages. 
The air enters one of these 
at A and is forced to pass 
through the water, lhen 
it passes upward and out 
along the other spirals C, C. 
The air is doubly purified, 
first by passing through the 
water, second in the removal 
of dirt by centrifugal action. 




Fig. 131. Parrett Air Cleaner for Removing 
Dust and Dirt 


Courtesy Ross-Wortham Company, Chicago 




















































180 


GASOLINE AUTOMOBILES 


Exhaust 
Gas Inlet 


Connection 
tVilh Starting r 
Battery 


V&poriza/ion 

Chamber 

K 


Mechamcaf 
'Btomizer 
Ball Bearings 

Center Opening 
" Throttle I 


'N 

Highspeed 
Nozzle JE 
p-G 


Parrett Air Cleaner. A similar device working on a different 
principle is the Parrett air cleaner shown in Fig. 131. Air enters 
at the top and is drawn downward through the central tube, the 
lower part of which is flared out and is supported on a metal 
float smaller than the bottom of the bell. The air passes between 
the two, through a very narrow opening, at high velocity. Large 

air bubbles can not form, 
Gasification chamber and because of the high 

velocity all heavy dust par¬ 
ticles are thrown directlv 

t/ 

into the water. The ris¬ 
ing purified air and mois¬ 
ture are separated by a 
series of baffle plates so the 
air finally passing to the 
carburetor is completely 
cleaned of dirt or dust. 

Deppe Gas Generator. 
Although not called a car¬ 
buretor by its maker, the 
Deppe gas generator re¬ 
places the ordinary car¬ 
buretor for the purpose 
of vaporizing kerosene. In 
appearance and in sec¬ 
tional drawing, as shown 
in Fig. 132, it is not unlike 
an ordinary carburetor 
with an extra-special some¬ 
what globular chamber 
above it, and below it the 
ordinarv inlet manifold, 

V 7 

which is exhaust heated. 
Some of the things claimed for it, when it is attached to ordinary 
cars with no change except in the vaporizer, are: perfect gas at all 
speeds; superior acceleration; no loading; increased high speed; lower 
slow speed on high gear; much greater fuel efficiency expressed in 
miles per gallon; handles all ordinary hydrocarbon liquids—gasoline, 



Fig. 132 

Courtesy of IF. P. Deppe, New York City 


Section of Deppe Gas Generator, 
Showing Construction 























































































































187 


GASOLINE AUTOMOBILES 

Vs 

kerosene, naphtha, etc., and mixtures of these; fixed metering adjust¬ 
ment which is not affected by altitude, temperature, or location; easy 
starting; less vibration of engine; and others. 

In Fig. 132, the fuel enters the float chamber A from below and 
passes through a horizontal passage B from which the two nozzles 
lead upward. The low-speed nozzle C draws its heated air through 
the primary intake D and mingles with this in the modified Venturi E. 
When the engine demands more fuel, it is supplied by the high-speed 
nozzle F, which gets its air from the auxiliary air valve G; this air and 
fuel mixture combine with the other in the chamber II, just above 
the Venturi and just below the center-opening throttle /. Up to 
this point it is not radically different from the average two-jet car¬ 
buretor with the auxiliary air valve. 

However, in the chamber just above this a mechanical atomizer, 
or rotating mixer on ball bearings J, is inserted. The idea is to com¬ 
bine the air and fuel particles more intimately through the rotation 
of this mixer within the zone of vaporization. The actual vaporizing 
chamber K is next above this. It is an annular passage around the 
highly heated exhaust gas chamber L, but inside of the outer exhaust 
chamber. This insures the absolute completion of the gasification 
started in other chambers, so that the mixture passing into the gasi¬ 
fication chamber M at the top and thence into the inlet manifolds 
and cylinders is sure to be a pure dry gas. 

Starting. To assist in starting, the primary-air passage is fitted 
with a choke valve of the butterfly type, which closes off this passage 
entirely so as to produce a rich mixture. Across the middle of the 
lower vaporizing chamber II , an electric resistance wire or heating 
coil is strung. The coil is connected to the starting battery. The 
connection is made so that the current passes through this heating 
coil as soon as it is turned on. This supplies the cold carburetor with 
the equivalent of the exhaust gas heat, which is available shortly 

after the engine has been started. 

Adjustments. As will be seen from the illustration, the low-speed 
nozzle and air opening are fixed, the only possible adjustment, setting, 
or change being m the alteration of the nozzle 01 in the quantity of 
primary air admitted. The high-speed nozzle is fixed similail} so 
that it cannot be adjusted, the high-speed air valve G furnish¬ 
ing the only adjustment. The adjustment of this is very simple; 


188 


GASOLINE AUTOMOBILES 


with the engine running, advance the spark pretty well to the 
limit, open the throttle lever to its maximum, and then vary the 
position of the nut N which governs the tension of the spring 0 
to the point where the maximum speed of rotation is obtained. 
This setting should be checked against actual high-speed running 
on the road, as there is usually a difference between the best road 
high-speed setting and the best engine-speed setting, with the car 
standing on the garage floor. 

Ensign Heavy Fuel Carburetors. A section through a new 
device recently perfected on the Pacific Coast, the Ensign car¬ 
buretor, is shown in Fig. 132 A, while Fig. 132 B is a horizontal 
section of the vortex mixing chamber which forms an important 
part of this. This device was designed to handle heavy fuels, but 
that shown in Fig. 132 A can be used for gasoline. As the figure 
shows the fuel enters a float chamber, thence into the bottom of a 
standpipe II, within which a suction tube A is set with its top 
opening slightly above the fuel level so that fuel must be drawn 
up by the air suction. This air enters at B and passing around 
the vortex, of which Fig. 132 B shows a better view, acquires a 
high velocity. Thus a considerable suction is exerted on the fuel 
which passes out through holes D into the whirling air stream, 
which vaporizes it. Should any fuel moisture remain the centri¬ 
fugal action of the air stream throws it against the walls whence 
it drips down through holes J into the mixture which passes 
through the narrowed throat K, thence makes a sharp bend to a 
horizontal direction, and another to a vertical flow entering the 
inlet pipe V on its way past the throttle M to the cylinders. 
The nature of this vortex chamber thins the mixture as it is pro¬ 
duced at I), and with increasing demands, and thus increasing air 
velocity, continues to thin it, so the vortex chamber automatically 
delivers a thinner and thinner mixture as the engine speeds up. 

Adjusting the Ensign Type 0. This model has two adjust¬ 
ments, air at A and fuel at G. Screw both of these clockwise to a 
closed position; then open G one and a half turns, and A one- 
fourth turn for four-cylinder motors, one-eighth turn for six or more 
cylinders. Start the motor and warm it up. Open the throttle 
to high speed and use G as a needle valve, adjusting to get the 
highest motor speed. Then refine this by adjusting A, one notch 


GASOLINE AUTOMOBILES 


189 


at a time. To start cold, open throttle M to slightly more than 
an idling position, and pull primer Y heavily before cranking. 


Ensign Fuel Converter. This 
company’s Model “N” device is 
intended to handle the very 
heaviest fuels, up to a dry boil¬ 
ing point of 600° F. It con¬ 
sists of three elements, the car¬ 
buretor proper, the gas producer 
and the temperature regulator. 
Fig. 132 C shows that the first 
is almost identical with the car¬ 
buretor shown in Fig. 132 A. 
To this is added the gas pro¬ 
ducer which consists of the fire 
screen U to which the heavy 
unvaporized fuel flows, the com¬ 
bustion chamber Q and the spark¬ 
ing element A which ignites it. 
This heats up screen U and the 
plate C below it so that these 
subsequently vaporize a larger 
portion of the fuel, and less of 

f 

it passes down into chamber Q 
to be ignited and thus vaporized. 
That is, this part of the device 
is self-regulating as to tempera¬ 
ture. The idling temperature is 
controlled by thermostat capsule 
N, operating temperature con¬ 
trol plug M. This is half full 
of alcohol, and its chamber is 
provided with means for cir¬ 
culating the hot mixture. As 
the mixture approaches 210° F. 
the capsule pushes the plug 
outward and closes the port 
0 reducing the draft and thus 



Courtesy Ensign Carburetor Company, Los 


Angeles, California 



Fig. 132 B. Horizontal Section of Ensign Car¬ 
buretor Showing Vortex Mixing Chamber 



Fig. 132 C. Section through Ensign Fuel 
Converter 


controlling the temperature. 
































































































190 


GASOLINE AUTOMOBILES 


Adjustment of Ensign Fuel Converter. Adjustment of this 
device is the same as the carburetor previously described, except 
for starting and with the addition of the spark plug care. In 
starting G is opened 1 turn, then E is filled with gasoline to fill the 
fire bowl up to the overflow F. If motor and converter are hot, 
prime very little; if motor has stopped but a few minutes, prime 
with Y on top of the flat bowl and start directly on the heavy 
fuel. Mith spark retarded adjust G to maximum engine speed. 
After engine has been running some time check this adjustment. 


CARBURETOR TROUBLES AND REMEDIES 

Engine Should Start on the First Turn. In starting a car cr 
any engine, whether located in a car or not, everything should be 
inspected so as to know if all is right before attempting a start. 
With the novice, this is somewhat of a task, but to the old hand 
it is so much of a routine task that he does it unconsciously. If 
all conditions are right, the carburetor is primed and the engine 
will start on the first turn of the crank. If it does not do so, 
there is a source of trouble which must be remedied first, and it is 
useless to continue cranking. The trouble may lie in the fuel 
system itself, but exterior to the vaporizer, or it may be in the 
ignition apparatus. It is well in a case of this sort to start with 
the gasoline tank and follow the fuel through each step until it 
apparently reaches the combustion chamber in the form of a, 
properly proportioned mixture of gasoline and air. 

To start with the tank—is there enough fuel in it not only for 
starting purposes, but enough to allow of making the proposed 
trip? This is readily ascertained by unscrewing the filler cap and 
inserting a measuring stick. For the purpose a. graduated rule is 
good, but not necessary; any stick or small branch of a tree will 
answer, or, lacking all these, a piece of wire can be used. 

Having verified the presence of fuel, the next question is: 
Does it reach the vaporizer as it should? Nearly all carburetors 
have a drain cock at the lowest point. Open this, and if fuel 
flows out in a steady stream, you may be sure that the pipe from 
the tank up to this point is not clogged. 

In either case, if there is no sign of gasoline when the tank 
contains plenty, it is apparent that the feed pipe is clogged. To 


GASOLINE AUTOMOBILES 


191 


remedy this, the method of procedure is as follows: Shut off the cock 
below the tank so that none of the previous liquid can escape, then 
drain off the carburetor and pipe into a handy pail. Next, open the 
union below the cock in the feed line and the one at the other end of 
the same pipe. At both places look for obstruction. Then clean the 
pipe out thoroughly, using flowing water, a piece of wire, or other 
means which are available at the time. 

Gasoline Strainer a Source of Trouble. If you find nothing here, 
look in the strainer of the carburetor to make sure that the flow is not 
stopped there by the accumulation of dirt and grit, filtered out of the 
fuel. The strainer should be cleaned often, but, like manv other dirty 
jobs, it is postponed from time to time. 

Should this source of trouble prove “not guilty” the carburetor 
itself becomes an object of suspicion. Is the float jammed down 
upon its seat, or are there obstructions which prevent the flow of fluid? 
Is the float punctured, or has one of the soldered joints, if a metal one, 
opened, or is it fuel-soaked, if cork? 

Bent Needle Valve=Stem. To attend to this sort of trouble, 
disconnect the priming arrangement, take the cover off the float 
chamber (it usually is screwed on with a. 
right-hand thread) and take the float out. 

An examination of the float, Fig. 133, 
will disclose whether it is at fault in any 
of the above-mentioned ways, all of which 
are comparatively easy to fix. If the float 
was jammed down, perhaps by priming, 
the act of taking it out will loosen it, 
provided that the stem of the float is not 
bent, and the needle valve or its seat is 
not injured. If the seat is scored, it should 
be ground-in just like any other valve, 
using oil and fine emery. A fuel-soaked 
cork should be thrown away if another is at hand to replace it, but if 
not, the cork float should be moved in its position on the stem so that 
it sets higher in the liquid. In other words, move the cork up suffi¬ 
ciently to compensate for its loss of buoyancy. 

In case of a punctured metal float or of loose solder, the only 
real remedy in either case is to rcsolder. It usually happens that a 



Fig. 133. Bent Needle Valve 



































































192 


GASOLINE AUTOMOBILES 


soldering outfit is not available out on the road, and some form of 
makeshift will be necessary in order to reach a place where one may 
be had. If the puncture is on the bottom, it is sometimes possible 
to accomplish this by inverting the float so that the hole comes at the 
top where the gasoline seldom reaches it. If the flow be reduced to 
make sure that the float will not fill up, it is possible to reach a place 
where a soldering iron may be procured. 

A remedy which might be tried in an extreme case of this sort is 
to fill the float to make it heavy, so that it will have a tendency tc 
sink. Then take a spring of small diameter, cut off a short piece and 
place it in the float chamber so that it opposes the sinking action 
of the now heavy float. By carefully determining the length and 
the strength of this spring, the same action is obtained as if the float 
were working all right. If the entrance of the liquid fuel is such that 
the sinking of the heavy float tends to close rather than open the gaso¬ 
line inlet, the spring would have to be on the bottom and fairly strong 
so as to oppose the action of gravity. But if the float works down¬ 
ward to open the gasoline passage, the spring will be at the bottom 
and very weak being there simply to prevent an excessive flow. 

Throttle Loose on Shaft. Now the carburetor trouble has been 
reduced to a minimum. The remaining troubles might be centered 
in a clogged spraying nozzle. But this nozzle is readily removed, 
and with it the trouble, if that be the offending member. If the 
spray is proven O. K., the throttle is ready for attention. If of the 
butterfly type, it may have become loose on its shaft, or, what is 
the same thing, the operating lever may be loose. In either case the 
shape and weight are such that it would swing into such a position 
as to cut off the entrance of gas to the inlet pipe and thus to the 
cylinder. If the throttle is of the circular sliding or piston form, it 
may not be connected to the throttle rod, but is stuck in such a 
position as to prevent the passage of gas. This sometimes happens 
when running, and then, apparently, closing the throttle does not 
stop the engine. The writer had this happen to him once at a time 
when it was absolutely necessary to stop. The only way that trouble 
was averted was by the instantaneous closing of the switch and 
the hasty application of the brakes. 

The last hope of finding trouble in the carburetor system rests 
with the inlet pipe. If the source of the trouble is not found else- 


GASOLINE AUTOMOBILES 193 

Ss 

where, take this off in search of misplaced waste or similar sub¬ 
stances. The size of the pipe is such that anything in it large enough 
to cause trouble may be instantly seen and removed. The only 
exception to this is a small hole in the inlet-pipe casting, which, if 
clogged even with a grain of sand or other material, will not only 
cause trouble with the mixture at all times, but will also be very 
hard to find, particularly if it happens to be of very small diameter. 

The valve, or cock, controlling the flow of liquid from the tank 
should be examined frequently and care be taken to keep it in good 
shape. It must act hard and must be tight, so that no gasoline flows 
when it is supposed to be shut off. If this valve does not act hard it 
is likely to jiggle shut during a long run and stop the engine by 
shutting off the gas supply from the tank. A method of fixing it— 
which, in general, is not to be recommended—is to open the cock and 
then hammer the handle so as to jam it tight against the seat, but in 
the open position. This makeshift will answer until a place is reached 
where the taper seat can be reground or tightened in place, if that is 
what it needs. In case the driver does not wish to do this, and the 
cock is of the two-way type—open when the handle is parallel to the 
axis of the pipe—it may be tied in the open position by passing a cord 
around the cock and pipe. 

Carburetor Adjustment. In adjusting the carburetor the 
worker should remember that the correct proportion varies from 11 
to 14 parts of air to 1 of gasoline vapor. It is not always possible 
to measure the two in just this way, but the adjustment is provided 
for in the carburetor. The tendency in carburetor construction is 
toward simplification and fewer adjustments. In making carburetor 
adjustments, always remember to make them with the motoi hot. 
A good plan is not to make any adjustments of this kind until after 

the motor has been running for an hour. 

Tool for Carburetor Nozzles. Many carburetor nozzles are made 
with a screwdriver slot to facilitate their removal. It will soon bt 
found, however, that the screwdriver is not so easy to use on these 
as a home-made tool. One useful form consists of a bar of 4 -inch 
steel-bar stock bent into the form of an L, the short end being flat¬ 
tened down into a screw 7 driver thickness and haidened. 

Starving at High Speeds. Many times, a motorist will experience 
the phenomenon known as starving at high speeds, that is, his 



194 


GASOLINE AUTOMOBILES 


motor will give better power and run faster with the throttle partly 
closed than when wide open. This happens when the auxiliary air 
valve does not open sufficiently to admit the large quantity of air 
needed at the widest throttle opening. The mixture, therefore, 
becomes too rich, and the motor starves. The auxiliary air valve 
usually has an outside spring, the tension of which is controlled by a 
milled nut, also on the outside. Then, when it is desired to make a 
change in the mixture, the nut is turned, altering the tension of the 
spring and thus altering the lift of the air valve; in this way the 
proper amount of air is admitted. To admit more air, the nut is 
backed off in order to weaken the tension and thus allow the air valve 
to open wider. To admit less air, the spring tension must be increased 
so that the air valve cannot open quite so far or stay open so long. 

Adjustments for Heating Water and Air Supply. On a large 
number of carburetors there are two more adjustments: those for 
heating the water and those for heating the air. The general run of 
carburetors are now water-jacketed to help vaporize the heavy fuels; 
during warm weather this may supply too much heat. For this 
reason, a cock is generally fitted to the hot-water line, which will allow 
partial as well as total closure. 

Similarly, hot air is supplied to almost all carburetors to vapor¬ 
ize the heavy fuels more quickly, a necessity if rapid acceleration, 
quick getaways, and other present-day demands are satisfied. In 
order to vary the hot air according to the weather or to cut it off 
entirely, some kind of a shutter is provided which can be locked in 
any position. When the days begin to grow warm late in the spring, 
the shutter is partly closed; during the heat of mid-summer, it is 
closed completely, and sometimes the connection with the exhaust 
manifold for heating the air is entirely removed from the car; when 
the temperatures begin to go down, the shutter is opened again, and 
in cold weather it is entirely open, and as much heat as possible is 
supplied the carburetor. 

Adjustment of the Nozzle. Nozzle Too Low. A rather common 
trouble is failure to start readily. One puzzled driver described his 
case as follows: 

The engine starts hard, necessitates pruning, and the primer must be 
held down for a long time. When this is done, it will start and run for a short 
distance, when it will stop and the same proceeding must be repeated. On 
taking the carburetor apart, everything was clean and apparently all right. 


GASOLINE AUTOMOBILES 


195 


If you are ever bothered in this way, you may be sure, granting 
that the spark is good, that the trouble lies in the fuel system. From 
the description of the trouble, it appears as if conditions were such 
as to starve the engine, although this was doubtless done uncon¬ 
sciously. This action is due to the fact that the gasoline level has been 
lowered so far that the suction of the engine does not draw up sufficient 
fuel for running. The fact that you have to prime to start and then 
prime to keep going, even this priming failing to work sometimes, 
would seem to prove that the engine is not getting enough fuel. The 
trouble is that the spray nozzle has been raised too high, so that the 
gasoline level is four or five times as far below the nozzle as it should 
be. The engine suction must raise the gasoline this distance before 



Fi-r 134 Section of Carburetor Showing Variation of Nozzle Level. First Figure, Correct; 
Second, Too Low—Engine Will Flood; Third, Too High—Engine Will Starve 


any of the fuel will get into the cylinder, and if the distance exceeds the 
height to which the suction can raise the fuel, none will pass over. In 
a case of this sort, priming only helps temporarily. 

Wrong Adjustment oj Jet JSozzle. The wrong location ol the jet 
nozzle results when the fuel level, as fixed by the float, is not high 
enough to give the proper flow of fluel into the vaporizing chamber. 
Drivers who have trouble with this are frequently puzzled by it, 
because they assume that the carburetor is properly adjusted before 
leaving the factory. This is not always the case. One young driver 


said: 

What is- the cause of this very puzzling knock? My four-cylinder engine 
develops a bad knock on a hill, which can only be eliminated by retarding the 
spark, but when that is done, the engine “dies , that is, gives no powei. I he 
effect is the same on level roads when the throttle is opened more than one 
third. 1 may have deranged the level of the gasoline within the carburetor 
while cleaning it. Would that have this result i 



















































































196 


GASOLINE AUTOMOBILES 


Now, this trouble is directly traceable to the change in the level 
of the nozzle made when cleaning and is made unconsciously. To 
quote from a plain statement of the effect of this change: 

By raising the spray nozzle, you lower the level of the gasoline relatively. 
Therefore, the liquid is less sensitive to the suction, which would reduce the 
amount of gasoline used. At knv speeds, there would be a tendency to starve 
the engine, which would, he most noticeable on hills. 

The trouble is that the spray nozzle has been raised so that 
the engine does not get enough fuel at slow speeds and on hills. 
By lowering this a small amount, Fig. 134, the engine will be able to 
suck up more fuel and the trouble ceases with the change. In making 

this change, be careful not 
to lower the nozzle too 
much at once, as the effect 
then is just as bad, the 
carburetor flooding at the 
slightest provocation. The 
better way is to lower 
the nozzle a very slight 
amount, say one-quarter 
of a millimeter, or perhaps 
one sixty-fourth inch 
would not be too much. 
Trv this level out very 
thoroughly, and when you 
are satisfied that it is not 
right, alter the level once more. The experience that you will get 
during the process will be worth all the time taken up in the series 
of successive adjustments. 

Cleaning the Carburetor. Cleaning the carburetor, then, should 
be done very carefully, until one becomes quite familiar with it and 
with the influence which movement of the various parts will have. 
In Fig. 135, a foreign carburetor partly taken down shows how 
the top part of the float chamber should be removed in order not to 
damage the delicate needle point at the bottom of the float by which 
the latter governs the fuel supply. The cover should be loosened and 
then lifted straight up until clear of all remaining parts. With the 
cover off, the float may readily be removed in the same way, the only 





197 


GASOLINE AUTOMOBILES 

Vs 


care being in starting it. As the amount, or length, of the needle point 
within the tapered seat is small, the float need be raised but a small 
amount to clear that. Then, it may be lifted out as one desires, since 
it usually is made from a half inch to an inch smaller in diameter 
than the chamber within which it works. 

Smallest Detail Important. The influence of the smallest things 
may be of great importance, as illustrated in Fig. 136. A man having 
a small runabout with a rather large air vent in the gasoline tank, 
which was located directly over the engine, was bothered, in climbing 
hills, by too rich mixtures. These not only caused the engine to 
smoke badly, but caused a lack of power. On investigation, he found 
that the carburetor was 
located below and nearly 
underneath the gasoline 
tank. On a hill, the 
gasoline flowed out of 
the air vent, down the 
side of the tank, and 
dropped into the air in¬ 
take, thus increasing the 
mixture. Obviously the 
cure for this was to 
change the air intake so 
that the overflow from 
the tank could not drop 
into it or into any part 
of the carburetor. The 



Fig. 136. Puzzling Carburetor Problem Solved 


sketch, Fig. 136, shows how he was advised to change it; the comment 
on the trouble and the proposed change were as follows: 

The addition of fuel, as you describe, to the air at the air inlet 
will seriously disturb the running of the engine and probably give 
so rich a mixture as to choke the engine. It is advisable to remedy 
this at once, and the best way to do so is to prolong the present air 
inlet upward and outward away from the gasoline tank w hich causes 
the trouble. To do this, have a sort of stove pipe made of galvanized 
iron, tin, or any similar metal. It should be long enough so that its 
top is as high as the top of the offending tank, then make a big, easy 
bend away from the latter. The opening, or mouth,of the pipe should 

















































108 


GASOLINE AUTOMOBILES 




Fig. 137. Method of Adding a Hot-Air Connection to 
Improve Carburetion 


he so formed as to take a screen, which is necessary to keep out the 
dust and should preferably be made removable, so that when the 

screen clogs with dust it 
can be taken off, cleaned, 
and replaced. For this 
purpose use a very fine 
brass gauze, which can be 
obtained at any hardware 
store at small cost. 

Pre=Heating the Air. 
One thing that gives a lot 
of trouble is the heavier 
fuel now supplied. It 
can be used successfully only by adding heat, the application of 
which may take one of two forms: a water or exhaust-gas jacket 
around the carburetor, or an arrangement pre-heating the air supply. 
The former cannot be added, but the latter can very easily. This is 

done, as shown in Fig. 137, by 
running to the air inlet for the 
carburetor a flexible metal 
pipe from a collector fastened 
to the exhaust manifold. This 
tubing can be obtained at any 
well-equipped automobile 
supply house, as can also the 
various fittings for the ex¬ 
haust pipes. In some cases, 
these firms carry the carbu¬ 
retor hot-air attachments 
also, but, if not, the maker 
of the carburetor can supply 
them at low prices. By the 
use of this attachment, the air 
drawn in through the carbu¬ 
retor passes around the very hot exhaust pipe, hence it is heated a 
great deal. 

Practically all late-model cars are equipped with a carburetor 
having a hot-water jacket and a special pipe for leading heated air to 


Fig. 138. 


Hot-Air Pipe to Carburetor on Belsize 
(English) Car 
























199 


GASOLIN E AUTOMOBILES 

SS 

\ 

Hie carburetor. In Fig. 138 is an English example of this, showing 
the carburetor connections on the four-cylinder Belsize. The pipe 
at the left is the inlet manifold and the one at the right, the hot-air 
pipe from exhaust manifold down to air inlet. In all cases this 
hot-air connection is made as short as possible. 

Causes of Misfiring. There are a number of vexatious things to 
make the novice and prospective driver peevish. Chief among these 
is the trouble known as misfiring. This may be described as a failure 
of the mixture to fire in any one cylinder. It is usually due to igni¬ 
tion, so that the term, as used now, means a failure to fire a charge due 
to an electrical cause. However, there are many common misfires 
which are due equally as much to a failure in the fuel-supply system, 
so that the latter meaning attached to the word is a misnomer. 

Among the causes which contribute to misfiring may be men¬ 
tioned ignition troubles, such as short-circuit in wires, exhausted 
battery, pitted or improperly adjusted vibrators of the coil, sooty 
or cracked plugs, loose connections or switch, dirty timer or com¬ 
mutator, punctured condenser, moisture in coil, wet wires or cables, 
water on distributing plate, dirt or wear on contacts in distributor, 
or dirt or wear in timer. 

Then, there are the misfires due in part or wholly to the fuel or 
carburetion system. These may be grouped or listed as follows: 

Carburetion and Fuel. Faulty mixture, sediment, or water in 
the carburetor, clogged gasoline strainer, leaky float, clogged spraying 
nozzle, bent float-valve spindle, stale gasoline, partial stoppage of 
fuel-supply pipe, hole or obstruction in intake pipe or manifold— 
these are not all the things that might happen, but are the principal 
ones which the writer’s experience has suggested as most likely to 
occur to cars in general. 

Foremost among the several difficulties which may be called 
common misfires is the lack of a proper mixture. A rich mixture 
containing a relatively large proportion of gasoline in proportion to 
air is never desirable, inasmuch as it deposits considerable soot upon 
the piston, cylinder walls, and valves, and is, moreover, a waste of 
fuel. The motor will seldom run well on a very rich mixture, and 
the carburetor should be so adjusted that no more gasoline is fed to 
the mixing chamber than is sufficient for the motor to develop its 
full power. The exact mixture may be found by experiment. 


200 


GASOLINE AUTOMOBILES 


A very rich mixture will cause misfiring; the motor will have a 
tendency to choke at other than high speeds and is likely to overheat. 
A lean or too thin mixture will, on the other hand, lower the efficiency 
of the motor, giving it a marked tendency to miss at high speeds, 
and is also accompanied by a popping sound in the carburetor. In 
this case, the needle valve should be adjusted to admit more gasoline, 
or, if due to an excessive supply of air, the auxiliary air valve should be 
adjusted to admit less air. 

Bent Float Swindle. A bent float spindle will cause missing in 
one or more cylinders. The float spindle may become bent or it 
may become jammed into its seat by too vigorous priming. This 
may be discovered by unscrewing the cover and lifting out the float. 
Considerable care should be taken in straightening out a bent spindle, 
and the metal should be placed upon a block of hard wood, another 
block interposed, and the spindle gently tapped with a hammer. 

Leaky Float. A leaking metal float or a fuel-logged cork will 
cause missing, owing to its uncertain and erratic action. A cork float 
should be thoroughly dried out and then given a couple of coats of 
shellac to prevent it from absorbing the gasoline. As a new float 
is not at all expensive, the driver will probably find it more convenient 
to put in a new one. A metal float must be soldered when it leaks. 
As the copper is thin and easily damaged, only a very little solder 
need be used. Precaution should betaken to keep the hot soldering 
bit away from the metal. 

A clogged gasoline strainer is often the cause of trouble, and 
this is about the first thing that the autoist should examine when 
the misfiring is apparently in the fuel-supply system. The brass 
gauze strainer should be frequently taken out and cleaned of any 
dirt that may have been filtered out of the gasoline. 

Obstructed Spraying Nozzle. Owing to the small needle-like 
opening in the spraying jet, it is not uncommon for a particle of grit 
to lodge in the orifice and partially stop the flow of gasoline. The 
obstruction will not always interfere with starting, but as soon as 
the motor speeds up, the amount of gasoline sucked through the nozzle 
will not be sufficient for the motor at higher speeds, and it will soon 
begin to misfire until the motor slows down to first speed. A leak 
in the intake manifold will cause misfiring and is often mistaken for 
ignition trouble. The cause may be due to loosening up of the bolts. 


GASOLINE AUTOMOBILES 201 

Summary of Gasoline System Troubles 

Carburetors should be among the last things to change in case of 
trouble. A black smoke from the exhaust will indicate too rich a 
mixture. Too thin a mixture may cause back-firing through the 
carburetor. 

Flooding of Carburetor. This may be due to the failure of the 
needle valve to seat properly, which may be corrected by grinding 
the valve; or to a punctured float which must be removed and the hole 
carefully soldered. It may also be due to the spraying nozzle being 
so adjusted that the opening is below the gasoline level. To remedy, 
raise the nozzle by easy steps until the correct level is obtained. 

Filling of Gasoline Tank. This should never be done by lamp 
or lantern light. 

Leaks in Gasoline Line. These must be repaired as soon as 
discovered. They may result in fire, destroying the car and endanger¬ 
ing the lives of its occupants. 

Filler Cap. The filler cap should uncover an opening in which 
is a strainer of gauze wire which should not be taken out, or, if broken, 
it should be replaced promptly. As an additional protection against 
small foreign particles getting into the gasoline system a funnel 
with a chamois skin through which the gasoline may be poured 
should be used. 

Grade of Gasoline. For ordinary use, gasoline from 56 to 68 
degrees test is most satisfactory. The former, called also stove 
gasoline, is the only kind obtainable now. 

Obstruction in Needle Valve in Carburetor. In searching for 
a clogged gasoline line, it is well to unscrew the needle of the needle 
valve and then blow through the valve. This will remove particles 
of dirt that may be there. 

INLET MANIFOLD DESIGN AND CONSTRUCTION 

Changes in Manifold with Engine Developments. Notwith- 
s anding the marked attention paid to minor details of design in the 
last three or four years, manufacturers have had no greater problem 
than that of vaporizing the fuel properly, quickly, and efficiently; 
this has led to considerable attention being given to inlet-manifold 
design. In the beginning, the inlet was a plain straight piece of 


202 GASOLINE AUTOMOBILES 



Fig. 139. Different Types of Inlet Manifolds for Four-Cylinder Engines 
Courtesy of N. W. Henley Publishing Company, New York City 



Fig. 140. Exterior of Studebaker Six Motor, Showing Particular Form of Inlet Manifold 
Courtesy of Studebaker Corporation, Detroit, Michigan 

























































203 


GASOLINE AUTOMOBILES 


tubing from what corresponded to the carburetor to the hole m the 
cylinder leading to the combustion chamber via the inlet valve. 
With the development of the four-cylinder motor, the majority of 
these were cast in pairs, and the pipe assumed a plain or modified 
Y-shape. Even at that, there was considerable chance for variety, 


as will be noted in the nine dif¬ 
ferent forms shown in Fig. 139. 

Changes from Fours to 
Sixes. With the coming into 
popularity of the six-cylinder 
form of motor, the inlet mani¬ 
fold received renewed atten¬ 
tion; for now there were more 
variables, and it was a question 
of the best combination of 
them. One solution of this, as 
seen on a medium sized block 
six, is illustrated in Fig. 140. 
Here, the distance which the 
fuel must travel to the two 
central cylinders (cylinders 3 
and -4) is so much less than the 
distance which the gases must 
travel to either 1 and 2 at the 






front or 5 and 6 at the rear 
that there was the possibility 
of these four cylinders being 
somewhat starved. To com¬ 
pensate for this, the central (E) 

part of the manifold where the 
three pipes to the cylinders join Fig. hi. Variet J^ Used on six ‘ 

that from the carburetor was Courtesy of N. if. Henley Publishing Company, 

Nexv York City 

made much larger, with the 

idea of providing a well, or reservoir, for gaseous mixture large 
enough so the two central cylinders could not use all its contents. 

The majority of designers, however, preferred to make the dis¬ 
tance for the gases the same in each case, which led to some of the 
shapes seen in Fig. 141. Here it will be noted that a central loop is 































204 


GASOLINE AUTOMOBILES 



used to make these distances come out equal in all but one case; in 
that, the cylinders are cast in threes with a single inlet for each group. 

Changes for Eights and Twelves. The coming of the V-type 
motors, both eights and twelves, has had another influence; for they 
came at the time when fuel was getting heavier and heavier. 
Designers were beginning to recognize the difficulty of vaporizing all 
the heavy fuel before it reached the cylinders, and, to assist in this, 
they began utilizing the manifold. Consequently, the majority, 
if not all, the eight- and twelve-cylinder engines have manifolds of the 


Fig. 142. View of National Twelve-Cylinder Motor from Above, Showing Inlet Manifold 
Courtesy of National Motor Vehicle Company, Indianapolis, Indiana 

loop type shown in Fig. 142. The unusual diameter of this is due 
to the water jacket around it; the water inlet is seen at A and the 
outlet to the carburetor water jacket at B. In this form, the unusual 
height is due to two things: the necessity of getting the carburetor 
between it and the cylinders, yet not too close for accessibility; and 
of having a sufficient volume to act as a storage reservoir, since 
each side of this (each half of the loop) serves six cylinders (four 
in the case of the eight-cylinder engine). This is a typical eight- and 
twelve-cylinder manifold, except that many of them have a pair of 
pet cocks let into it for priming or cylinder testing purposes. 





GASOLINE AUTOMOBILES 205 

Heating the Charge. The method of heating the charge has 
taken a number of forms. In a simple four-cylinder motor of the 



Fig. 143. Type of Combination Inlet and Exhaust Manifold Which Improves Vaporization 


L-head type, like the Ford, it has been possible to develop a combina¬ 
tion inlet and exhaust manifold (a single casting which would replace 
both of the former manifolds) which would give the heating effect 
desired in the inlet portion. Fig. 143 shows one way in which this 
is done and shows the central plate, or rib, between the two manifolds, 
which is heated to a high temperature by the exhaust gases, and thus 



Fig. 144. Form of Water-Jacketed Inlet Manifold Used on Marmon Motor 
Courtesy of Nordyke & Marmon Company, Indianapolis, Indiana 


has a large influence on 
on the other side of it. 


the final vaporization of the inflowing gases 
It is claimed for this form that it will save 






























200 


GASOLINE AUTOMOBILES 


from 25 to 40 per cent of the fuel used, and, even though this 
claim is not borne out in all cases, the fact that there is a saving 
shows that this is a correct method. Many of the more modern 
motors are not only incorporating this as a method of saving fuel 
and increasing the motor’s efficiency, but also of reducing the 
number of parts in the machine, the opportunities for trouble, and 
possibly of reducing weight. 

Another way in which the ordinary four- and six-cylinder 
inlet manifold has been altered is by the addition of the water 
jacket, previously mentioned. A typical example of this is seen in 
Fig. 144, which shows a water-jacketed inlet manifold on a six- 
cylinder motor, although the water-pipe connections are not visible. 

Changes in Construction of Manifold. In addition to the 
design, the construction of inlet manifolds has been of marked 
influence. Thus a manifold of aluminum, iron, or other cast 
metal is usually quite different from what a manifold for the same 
engine would be if made from copper or steel tubing. In addition 
to the limitations of the process of production, there would be the 
changes which the surface produced would have. Thus, a casting 
would have a more or less rough surface, while a drawn tube 
would be perfectly smooth. This allows the use of a slightly 
smaller diameter and more abrupt bends with the latter than with 
the former. Similarly, the fastening means have had an influence. 
Cn a number of block-cast motors, the manifolds have been cast 
integral with the cylinders, thus taking further advantage of the 
heat generated within the motor, for fuel vaporizing purposes. It 
is for this type of motor that the horizontal-outlet type of carbu¬ 
retor has been developed. In this type the volume of vaporizing 
space beyond the spray nozzle is at a minimum, that is, they have 
been designed simply to mix the fuel spray and air, while the 
highly heated inlet passages do the actual vaporizing. 

Hot Spots in Manifolds. A later trend in inlet manifold has 
to do with easier vaporization of the heavier fuels of today. Due 
to the high boiling point an external source of heat has been 
found necessary in this, and one of the ways in which this has 
been done is by means of the “hot-spot” manifold. To explain 
this simply, the inlet manifold is so constructed that a portion of 
it consisting of solid metal is in constant contact with the exhaust 


207 


GASOLINE AUTOMOBILES 

SS 

manifold so that in continuous running this solid metal in the 
intake manifold becomes heated, perhaps to a high degree. Further¬ 
more, this “hot-spot is so located in the inlet passages that all 
fuel must pass over it before passing to the cylinders, that is the 
last thing before passing in. A sharp bend in the inlet passage at 
this point does it, with the result that any unvaporized particles 
remaining in the fuel gas at this point are thrown against this 
highly heated spot and vaporized there, instead of being carried 
into the cylinders as liquid particles, as would be the case without 
this heated spot. One of these using the Stromberg “L” car¬ 



buretor is that of the Chalmers, shown in Fig. 144 A, said to pro¬ 
duce more power, greater economy, and more rapid acceleration. 

Another similar arrangement is used on the Hinkley truck 
engine as shown in Fig. 144 B. This engine is really a modifica¬ 
tion of the Class B Government engine and resembles it very 
closely. As will be noted in the drawing, this arrangement is 
very similar to the Chalmers, the exhaust and inlet being slightly 
different to facilitate easy and quick removal and replacement. 

As has been stated frequently, much heavy fuel is available 
on the Pacific Coast and at low prices, so out there considerable 


















































208 


GASOLINE AUTOMOBILES 


effort has been expended on using these cheaper but heavier fuels. 
A modification of the hot-spot arrangement, designed to be used 
on Ford cars is shown in sketch form in Fig. 144 C. Here the hot 



Fig. 144 B. Hot Spot Manifold Arrangement on Hinkley Truck Engine 
Courtesy Hinkley Motors Corporation, Detroit, Michigan 


spot projecting into the exhaust manifold is not alone made very 
large but the outer or heating surface is increased by the addition 
of fins similar to an air-cooled engine. This adds metal to heat 
up and hold the heat, which is what the heavier fuels like distil¬ 
late must have. In addition, as will be noted, the carburetor is so 
constructed as to spray all the fuel oil directly into the interior of 
this highly heated mass of metal, the gasified parts coming down 
into the intake manifold. This heated mass of metal is thus the 
entire dependence for vaporization in this case, the actual car¬ 
buretor part of the device having been eliminated. It would seem 
that this carries the hot-spot or hot surface plan almost too far, 



Fig. 144 C. Far-Western Carburetor Which Is All 

Hot Spot 


its original intention having been for use as an auxiliary solely, 
the hot surface vaporizing only those heavy globules of the liquid 
which the spraying and atomizing and air mixing did not or could 



































































GASOLINE AUTOMOBILES 


209 


not break up and vaporize. In short it was intended originally 
only as a clean-up device, following and wholly dependent upon 
the carburetor. The device in Fig. 144 C aims to make the hot 
surface become hot surface, vaporizer and clean-up device all in one. 

Another version of the heated manifold surface is shown in 
Fig. 144 D, the manifolds of the Yelie tractor. Here the first 
part of the inlet manifold is highly heated by constructing the 
two manifolds as one, the inlet consisting of a straight vertical 
passage through the center of the exhaust passages, just as the 
detail at the left shows. This would give the high heat necessary 
for the original vaporization or cracking up of all the fuel, but to 
insure continuation of this condition, that is, to prevent any of 
the mixture condensing out into liquid again, the second portion 



across the top of the cylinders is water cooled. In this condition, 
the gas would be too hot to enter the cylinders, hence it is cooled 
by means of air-cooling fins or ribs along the last portion of its 
length. As a permanent gas has been produced by the previous 
steps, this carries with it small possibility of any condensation. 

The real flaw in the hot surface method is that it is of no 
help whatever in starting, since it does not begin to work until 
after the engine has run for some time, and heated up. And poor 
starting is really more drawback than running on heavier fuels. 

Inlet Manifold Troubles. The principal inlet manifold troubles 
are air leaks, which dilute the mixture beyond the carburetor, making 
it and its many elaborate adjustments more or less useless. These 
leaks may be due to leaks around joints, connections, or gaskets or to 
porous castings. If the inlet manifold is of copper or steel tubing, the 





















































210 


GASOLINE AUTOMOBILES 


idea of a leak can be dismissed, but, otherwise, a porous pipe can be 
discovered at idling speeds by squirting gasoline upon the suspected 
surface of the manifold and noting if the motor speeds up. If it does, 
this is a sign that some of the gasoline has been drawn through the 
holes in the manifold, enriching the mixture. 

The leaks around joints, connections, or gaskets can be found in 
much the same way. When the leak is found, the joint should be 
tightened if possible, or a new gasket should be put in, or both. In 
the case of the porous manifold casting, it can be painted with a fairly 
heavy paint while hot so that the pores of the metal are well opened. 
Then, after this has dried in thoroughly, another coat will probably 
finish the job. If this does not prove to be the case, special cement 
for filling porous castings can be purchased and applied; or, best 
of all, if the case is a bad one, an entirely new manifold should 
be put in. 

FUEL SUPPLY 

For storage of the fuel required for the propulsion of a car and for 
feeding the fuel to the carburetor, many different systems are in use. 

Tank Placing. In automobiles, the gasoline tanks are generally 
placed under the front or rear seats, or under the frame at the rear. 
In many types of runabouts and roadsters, the tank is placed above 
the frame at the rear. 

Fuel Feeding. When the tank is at the rear, or when it is under 
the front or rear seat, no special provision is necessary, under ordinary 
circumstances, to insure a positive flow of the liquid fuel to the 
carburetor. 

Gravity . With the tanks placed high, the gasoline can be 
depended upon to run down to the float chamber by gravity. In 
mountainous districts it is sometimes found, in climbing very steep 
hills, that the angle becomes such that the fuel will not flow, especially 
when the tanks are under or back of the rear seat, or when they are 
nearly empty. , - 

A means of getting around this difficulty is to place an auxiliary 
tank of one or two gallons capacity on the front of the dashboard, 
behind the engine and under the bonnet, and run a pipe direct from it 
to the carburetor. When the car is in a level position, this auxiliary 
tank fills automatically from the main tank, but a simple valve pre- 


GASOLINE AUTOMOBILES 211 

vents the contents of the auxiliary tank from running back when the 
machine is tilted up. In this way a sufficient supply for 15 or 20 
miles running is placed in a position to reach the carburetor under 
any possible road condition. 

Air Pressure. With the tanks placed low, whether under the 
frame or above it, it is necessary to feed the fuel to the carburetor 
by more positive means than gravity. One of the commonest sys¬ 
tems involves pumping a low air pressure into 
the tank above the fuel, so that this pressure 
forces the liquid out regardless of the relative 
heights of tank and carburetor. Ordinarily, 
a small hand pump is sufficient to provide 
such air pressure, though in modern auto¬ 
mobiles equipped with compressed-air starting 
devices, or compressed-air tanks for filling the 
tires, provisions can be readily made for sup¬ 
plying the tanks with air from these sources 
for the purpose of feeding the fuel. 

Exhaust Pressure. A system that is 
much used for providing pressure in the fuel 
tanks, though not so highly regarded as in the 
past, is to tap the exhaust piping and to take 
from the connection a pipe line that permits 
the entry of a certain amount of the exhaust 
gases into the fuel tank. A simple automatic 
valve controls the pressure and shuts off the 
admission of gas when the pressure rises above 
the very low maximum required. In a sys¬ 
tem of this character there is no possible 

Fig. 145. Section through the 

Stewart Vacuum Gasoline danger of fire, not onlv because the exhaust 

Feed Device . 

gas is very quickly cooled in passing through 
a length of small piping, but also because the contents of a gaso¬ 
line tank is ordinarily not igmtiable, because of the lack of any an 
to support the combustion. 

Sooting up of the automatic valve is the commonest trouble 
with this system. 

New Vacuum Feed Device. The many troubles incident to the 
use of the rear tank location with pressure feed have hi ought about 


ZJir Vent 




From Gasoline^ 
f'r—. T ank 























































212 


GASOLINE AUTOMOBILES 


the production of a new device, which is called the Stewart vacuum 
feed. This is a small compact circular unit, which is placed on the 
dash under the hood for use with a rear tank and, when so used, 
eliminates the pressure feed. A sectional drawing of this is shown in 
Fig. 145. It may be described as follows: There are three connec¬ 
tions at the top, one to the gasoline 
tank, one to the intake manifold, 
and one to the air vent. Through 
the medium of the intake-manifold 
connection, the motor suction is 
communicated to the tank, for 
that is what the device amounts 
to. This produces a vacuum and 
opens the valve connecting with 
the gasoline tank. That, as well 
as the connecting-pipe line, being 
air tight, gasoline is drawn in to 
fill the vacuum, flowing into the 
upper chamber with which the 
gasoline tank communicates. 

This has a valve connection 
to the lower chamber, operated by 
means of a float; it in turn is con¬ 
trolled by the intake manifold sue- 
tion, through the medium of the 
system of levers. By it, the lower 
chamber is kept filled to a fairly 
high level, whence feed to the 
carburetor is by gravity. This 
method thus does away with all 
the troubles of the pressure sys¬ 
tem, at the same time allowing of 
the accessible and advantageous 
rear tank location. It is placed as 
high as possible on the inside of the dash under the hood, hence there 
is never any trouble with the gravity feed even on the steepest hill. 
In one test, this vacuum-feed device increased the mileage of the car 
per gallon of fuel by more than 22 per cent. 



§SH> 


To Carburetor 


Fig. 146. 


Section through Carter Automatic 
Gravity Fuel Tank 


Courtesy of Carter Carburetor Company, 
St. Louis, Missouri 































































































213 


gasoline automobiles 

Vs 

Pressure-Operated Feed Device. Carter System. Since the 
introduction of the Stewart device described above, a number of 
devices acting on somewhat different principles have been brought 
out. In the Carter automatic gravity tank, as it is called, the suction 
and compression strokes of the motor are used to furnish the pressure 
which operates a simple diaphragm pump, first in one direction, then 
in the other. This diaphragm pump is shown at the right of Fig. 14b 
and is marked A. As shown, this connects through a ball check 
valve B with the main gasoline tank, the strokes of the diaphragm 
pump drawing fuel into the central well C, which, when filled, over- 



Fig. 147. General Layout of Church Fuel Supply System as Applied to a Car 
Courtesy of Automatic Carburetor Company, Chicago, Illinois 


flows into the main tank space D. From here it flows by gravity 
through the pipe E to the carburetor. The tank is made in but one size, 
that holding about a pint. Above the ball check, a spring-operated 
valve of simple design prevents the fuel from flowing out when the 
ball has been drawn off its seat. As the tank gets very full, the float 
will rise, and the needle at the upper end of its stem will seat at the 
top, cutting off the air supply. Without any air in the opening tank, 
an internal pressure will be created which resists the opening of the 
valves and thus the further supply of fuel until more has been drawn 
off and the float drops down and uncovers the air hole again. 














































GASOLIN15 AUTOMOBILES 


211 


Gasoline from Tank. 

Gasoline \/apor from 
Carbureter 


5creer, 


It is advised that this tank be connected to the engine in any con¬ 
venient place, except that near the exhaust manifold. When the tank 
has been connected and is ready for use, prime it with about half a 
pint of gasoline poured in through the filler cup on the top. After 
this has been done, the tank will continue to operate as long as 
there is fuel in the rear tank. 

Church System. In the 
Church system, the compres¬ 
sion, y or explosion pressure, is 
used to lift the fuel through the 
medium of the specially designed 
check valve. A general layout 
is shown in Fig. 147, in which it 
will be noted that the check 
valve is mounted in the rear 
cylinder in place of the pet cock. 

Through this, the pressure is 
maintained in the main tank at 
the rear of the chassis, thus 
forcing gasoline to the auxiliary 
tank. Normally, the check 
valve will produce about one 
and one-half pounds pressure on 
the main tank, but the arrange¬ 
ment of the system is such that 
this maximum pressure is auto¬ 
matically increased to meet the 
conditions existing at any time. 

In this sketch, it will be noted 
that the pressure line is con¬ 
structed with a T, one part of 
the pressure going to the auxiliary tank where it is regulated by 
means of a float, and the other going to the main fuel tank. 

By referring to Fig. 148, which shows a section through the 
auxiliary tank, the regulation of the pressure will be made clear. 
When the supply in the auxiliary tank gets low, the float F drops down; 
this moves the rod S down also. The downward movement of the 
rod forces down the valve R, which prevents the air escaping through 



Check- 

Valve 


/ Condensing 

Cir from Cngme 
and Tank 


Fig. 148. Section through Church Tank, 
Showing Construction; Also 
Section of Check Valve 







































































GASOLINE AUTOMOBILES 215 

Vs 

the condensing tube, and thus the entire pressure in the system is 
exerted upon the main tank with the result that the pressure rises 
there. When more fuel is forced to the auxiliary tank, the float rises 
and allows the air relief valve R to rise; this opens the passage to the 
condensing tube again, so that the air can escape in that way and 
relieve the pressure upon the main tank. In this way, a balancing 
effect is produced, which automatically keeps the auxiliary tank well 
supplied. 

From this tank the fuel flows by gravity to the carburetor. 
I here is, however, an additional and valuable feature of this system. 
On top of the tank will be found a vapor outlet 0, and in the sketch 
it will be noted that this is connected back to the carburetor. In this 
way any vaporization which-occurs in the auxiliary tank is utilized. 
This has the double advantage of being a source of economy and of 
keeping the system closed against the entrance of dust. Provision is 
made, despite this, for cleansing out sediment, by a drain plug at the 
bottom of the tank. The gasoline check valve will be noted at the 
top, this operates in conjunction with the float stem and air-relief 
valve, that is, the rising of the float in a full tank will automatically 
cut off further supply by means of the check valve, as well as by open¬ 
ing the air-relief valve at the bottom. Similarly, the downward 
movement of the float, which closes the air valve and causes more 
fuel to be forced into the tank, automatically opens the gasoline valve 
so this fuel can flow in. The enormous reduction of pressure elimi¬ 
nates all possibility of danger which might be thought of in connection 
with the mingling of exhaust gases and gasoline, their temperature 
being reduced simultaneously with the reduction in pressure. 

Fuel Pumps. In a few automobiles, the expedient of providing 
a small motor-driven gasoline pump has been tried in place of the car¬ 
buretor with a float chamber. As long as the engine is running, the 
pump forces an excess of gasoline from the tank through the car¬ 
buretor chamber, from whence the surplus is returned to the tank 
through an overflow, placed at a certain height so as to constantly 
maintain a proper level. 

Piping and Connections. In arranging the piping system for 
the fuel supply of a gasoline automobile, the first essential is to use a 
soft brass or copper tubing that can be depended upon not to break 
from the vibration to which it is subjected. 


216 


GASOLINE AUTOMOBILES 


As a further safeguard against breakage, and to allow alterations 
in the relative positions of different parts, due either to the straining 
of the machine while it is in use or to a change of adjustments when 
it is disassembled or reassembled, loops or coils introduced at proper 
points in a pipe line are of great advantage. 

Stop cocks close to the tanks are an excellent safeguard against 
fire, since they permit the shutting off of the fuel supply in the case of 
any breaks in the line. Such safeguards should always be provided. 

With reference to the pressure system of fuel feed, there is hardly 
any limit to the precautions which must be taken to avoid leaks. The 
smallest leak puts the system out of commission as soon as the pressure 
leaks down to a point where the fuel will not rise to the carburetor. 
When this occurs, the engine cannot be operated until the leak is 
found and fixed. To avoid leaks, many drivers go over all joints 
frequently and likewise replace all old packing. In addition, they 
wipe the joints with soap to prevent leakage and then cover them on 
the outside with tire tape or similar flexible material which can be 
wound on in such a way as to stay permanently. The rapid adoption 
of the Stewart device, since it was brought out in 1914, shows better 
than anything else how troublesome was the pressure-feed system. 
Statistics for 1914 cars showed that in 237 different models, 109 had 
the gravity tank under the seat, and 31 in the cowl, this making 140 
with gravity feed, leaving 97 with the rear-pressure tank location. 
Similar statistics for 1915 show 52 per cent in favor of the rear tank 
location, while 1916 shows almost 66 per cent with rear location, and 
34 per cent vacuum fed. 

Reserve Tanks. To guard against the annoying mishap of 
having the gasoline give out while an automobile is in use, perhaps 
remote from any source of supply, many cars are now provided with 
reserve tanks which hold back one or two gallons of gasoline. This 
reserve cannot be used except when it is fed into the system through 
the deliberate intent of the operator. 

In its simplest and one of its best forms, a reserve tank takes 
the shape of a partitioned-off portion of the main tank, into which 
the gasoline automatically flows through an opening at the top when 
the tank is filled. It cannot pass to the carburetor until a special 
valve in the bottom is opened and the fuel allowed to flow back into 
the main tank. 


GASOLINE AUTOMOBILES 


217 


A later and even more simple provision is the use for the gasoline 
tank of a three-way outlet cock which has a fairly long extension up 
into the tank. 1 he extension tube is open at the top and has a hole 
near the bottom of the tank which communicates through a branch 
tube with the third way of the cock. When the outlet cock is set for 
normal flow, the fuel feeds until the level reaches the top of the exten¬ 
sion; at that point it stops flowing. This is the warning to the driver 
that his fuel is low. Then all he has to do is to turn the outlet cock 
to the other position, thus allowing the fuel to feed from the bottom 
hole of the extension tube. The remainder of the fuel, that is, the 
amount represented by the difference in level between the top and 
bottom of the extension tube, will carry the car to the next fuel station. 

Fuel Gages. The development of depth and quantity indicators 
has received much attention in the last few years, with the result that 
practically all new cars have some form of gage on, or in, the fuel 
system. On rear-pressure tanks, it is usually located on the tank, so 
the driver must go to the rear of the car to see how much fuel he has 
left, but on cowl tanks or those located under the seat, it is possible 
to have the gage set on the instrument board or the dash, as the case 
may be, so that it is in plain sight. Practically all the gages give 
indications in gallons and fractions, so that wffth the gasoline gage and 
odometer in front of him, and knowing how many miles he averages 
to the gallon of fuel, no driver need w r orry about having gas. He can 
readily figure ahead and keep sufficient on hand for his needs. A 
device has been produced to give dashboard indication of rear-tank 
capacities, but this is so complicated and expensive that it is little used. 

FUEL SYSTEM TROUBLES AND REPAIRS 

Failure of Fuel to Flow from Full Gravity Tank. Many times 
the fuel will not flow from a gravity*tank which is full. This may be 
because the air holes in the filler have been stopped up so that no air 
can enter. By cleaning out the holes, if there are any, drilling some 
if there are not, or by loosening the filler, this can be remedied. For 
this reason, it is well not to use a gasket or washer on a gravity tank. 
On a pressure tank, just the reverse situation exists, and it is advisable 
to use a rubber or leather washer at the filler cap. 

Fuel Line Obstructed. Many times an obstruction in the fuel 
line will be found at a very low point or sharp bend, where dirt in 


218 


GASOLINE AUTOMOBILES 


the fuel has gradually collected until there was enough to cut off 
the flow. A good way out of such a difficulty is to close connections 
at the tank and at the carburetor, take the entire fuel line off and 
blow it out with compressed air. This will clean it thoroughly. 

Lock on Fuel Line. The garage or repair man can insert a very 
efficient lock on any car by putting into the fuel line at a convenient 
point a shut-off cock which works with a removable key. These are 
readily obtained, and any good workman can install one in a couple 
of hours. Many owners of cars would be glad of an efficient lock 
and would be willing to pay well for one. This one has the advantage 
of being simple, cheap, and effective. 

SUMMARY OF CARBURETOR INSTRUCTIONS 

Q. What is a carburetor? 

A. A carburetor is a device for vaporizing liquid fuels, and for 
adding to them, when vaporized, the proper amount of air for imme¬ 
diate and complete combustion. 

Q. How many types of carburetors are there? 

A. Three: the surface form, now out of date; the filtering type, 
no longer used, except on one or two English cars; and the spraying 
type, to which all modern devices belong. The first was useful only 
with the very light and extremely volatile fuels of ten and twenty 
years ago. 

Q. What are the essential units of a spraying type of carburetor? 

A. The essential parts of a spraying type of carburetor are: 
a float chamber with a float arranged to regulate the level of the 
inflowing fuel; a needle and nozzle, or spraying device, which should 
preferably be adjustable; an air opening, which may be variable or 
not, which may be in multiple form or not, which may have automatic 
valves to regulate its size or not; and a throttle valve to control the 
quantity of mixture passed into the cylinders. As an important 
auxiliary, the needle, nozzle, or spraying device, whatever its form, 
should be placed in a special vaporizing chamber, of a size and shape 
to give the best results.' 

Q. Do all these appear in all modern carburetors? 

A. Practically all, in one form of another, and also a consider¬ 
able number of additional parts. Thus many carburetors have two 
or more nozzles, or spraying devices;quite a few have two air openings, 


GASOLINE AUTOMOBILES 


219 

one of which is controlled by an automatic valve, some have three air 
openings; many, in fact most, of the modern devices have a method 
of heating the vaporizing chamber, or the space immediately above or 
below it, so as to facilitate complete vaporization, as well as to quicken 
the action; some have air valves in the form of steel balls; others 
have pistons and dash pots to eliminate sudden movements or changes 
in operation; many have auxiliary devices intended to give a special 
starting mixture; practically all have removable strainers for cleaning 
the fuel, some having two different forms of strainer. 

Q. What is the generally accepted form of needle valve, or 
spraying nozzle? 

A. There is no one accepted form, although the majority of 
carburetors have spraying nozzles, or needle valves, which come into 
one of four classifications. These are: the hollow nozzle with an 
opening at the top, slightly smaller in inside diameter than in outside, 
so that the spray of fuel is opened out in a fan-like form; the same form 
with an internal needle having a long tapered point and screwing up 
into it from below, this giving a means of adjustment which the plain 
hole does not; the same plain tube and hole, with an external needle 
having a tapered point and screwing down into it from above (in 
this, the body of the needle divides the spray of fuel); and the form 
of hollow nozzle in which the fuel is forced to flow outward through a 
series of holes, then upward to an outlet which consists either of an 
additional series of holes or a very fine annular ring. Either form 
gives the same result, a very fine and somewhat extended spray of 
fuel. The last form is sometimes modified to the extent that this 
annular ring of fuel, where it emerges into the vaporizing chamber, is 
as much as 3 or 4 inches in diameter. 

Q. What is the purpose of the auxiliary air valve? 

A. To supply additional or auxiliary air at the higher and 
highest speeds. Without this, the heavy suction of high speeds <rr 
hard pulling is very likely to produce too rich a mixture, that is, a 
mixture with too much fuel and too little air. 

Q. Is there any disadvantage in this? 

A. Yes. It has been found by experience that a motor will not 
operate well or give its extreme power or greatest speed on a rich 
mixture. Rather, at its highest output, the mixture should tend 

toward leanness. 


220 


GASOLINE AUTOMOBILES 


Q. How does the auxiliary air valve remedy this? 

A. By adding air when the motor suction gets strong enough to 
open the auxiliary air valve, the amount added being in direct propor¬ 
tion to the strength of the suction. 

Q. What other disadvantage is there in over rich mixtures for 
high speeds? 

A. An over rich mixture at high speeds shows a noticeable lack 
of economy, as at these speeds a great amount of gas is being used, 
and, if too rich, the gasoline fuel is being used up very rapidly. The 
makers of practically any carburetor equipped with an auxiliary air 
valve will guarantee a saving of 20 per cent in fuel consumption when 
it replaces a carburetor which has no auxiliary air valve. 

Q. Why are some carburetors water=jacketed? 

A. The conversion of a liquid like gasoline into a vapor is a 
chemical action which needs heat to complete it. If no heat is sup¬ 
plied, it will be taken from surrounding objects, or else the vaporiza¬ 
tion will not be completed. This abstraction of heat from the sur¬ 
roundings can be noticed in unjacketed carburetors in the form of frost 
or snow forming on the outside of the vaporizing chamber. The 
water-jacketed carburetor has the hot water of the engine system 
circulated through it to supply the needed heat, and thus assist and 
complete the vaporizing of the fuel. 

Q. Why are some carburetors supplied with hot air? 

A. This is done for the same reason. The pre-heated air is 
supplied to vaporize the fuel, instead of using cold air and supplying 
heat from other sources. In principle, it is practically the same as 
the other. 

Q. When hot air is supplied, how is this heated? 

A. Generally a stove, or a hollow member around the heated 
exhaust pipe, is connected by metal tubing to the air inlet of the car¬ 
buretor; in this way all of the air drawn in is forced to pass around the 
exhaust pipe, which heats it. This is not always the case, some 
makers using air sucked in from around the heated cylinders. Still 
others use an exhaust jacket on the carburetor, and draw the cold 
air supply in around this, so that it is heated. 

Q. What difference does the fuel make in this heating method? 

A. On the heavier fuels, such as kerosene, alcohol, distillate, and 
mixtures of these with gasoline, a great quantity of heat is necessary, 


GASOLINE AUTOMOBILES 


221 


as these heavier fuels are more difficult to vaporize and are also slower 
to start vaporizing. This means an extra supply of heat at starting 
time, and more than the usual supply at all times. It works out, in 
the direct use of exhaust gases, through a small pipe tapped into the 
exhaust manifold, thus giving the highest available temperature. 
This is used through the carburetor jackets, but, in addition, the air 
supply to vaporize the fuel is heated. Another vaporizer of heavy 
fuels, which has been quite successful, places heavy metal weights 
inside the carburetor in the upper part of the vaporizing chamber and 
then forces the exhaust gases through hollow passages in these. In 
this way, the weights are heated up, and this heat is transmitted to 
the gas and air; the size and nature of the metal gives an equable 
supply of heat, regardless of the exhaust gases. 

Q. What is the throttle valve? 

A. A valve placed in the pipe between carburetor and cylinders 
to vary (or throttle) the quantity of mixture flowing to the latter. This 
is generally connected to the throttle lever on the steering wheel, and 
to the accelerator pedal. General practice in driving, after the initial 
stages of learning, is to set the hand throttle at some medium point, 
and thereafter to vary the speed of the motor by means of the foot. 

Q. What is the general form of this throttle valve? 

A. The butterfly throttle is used more than any other form, 
although the piston valve is considerably used. The butterfly is the 
simplest form possible, consisting of a thin circular disc the size of the 
interior diameter of the inlet pipe, fastened at the middle to a round 
shaft which extends across the pipe, and has a lever fastened on the 
outside extension. When this lever is turned so that the disc lies at 
right angles to the pipe, the passage will be shut off; when it is turned 
up parallel to the pipe, the passage will be wide open, for the disc is so 
thin as to offer practically no resistance to the gases. The piston type 
of throttle may be arranged so as to rotate or to slide. When it 
rotates, it is generally constructed with holes in its walls which register 
with the opening in the pipe, according to its position. When it 
slides, these holes are generally continuous at one end, this being 
moved along so as to register with the opening in the pipe. Another 
type of throttle is the swinging, or flap valve. This is so shaped 
as to swing from side to side, closing the passage entirely in one 
position, and leaving it entirely open in another. 


222 


GASOLINE AUTOMOBILES 


Q. What is a Venturi tube? 

A. This is the essential principle of the inner member of the 
Venturi meter, invented for measuring the flow of water. It consists 
of two cone-shaped tubes diverging in opposite directions, with the 
proper relation of angles to one another and to the diameter of the 
smallest point, or meeting point, of the two tubes. The larger angle 
should be at the bottom, or entering end for the gases; the nozzle, 
or needle, should be just at or just below the smallest diameter; and 
the gases should flow through from end to end, that is, air in at one 
end, gas in at the middle, mixture out at the other end. In the true 
Venturi tube, the bottom angle is 30 degrees, the top angle 5 degrees. 

Q. When more than one nozzle is used, how are they connected? 

A. In practically all multiple-nozzle forms, the arrangement is 
such that the second (and later) nozzles are brought into action by 
increased demand from the engine, that is, automatically. In one 
case, a flap valve covers the second nozzle; but, as the suction increases 
this is drawn up and the nozzle is uncovered; having its own air 
supply, the nozzle begins to function as soon as it is uncovered, the 
amount of gas supplied by it depending upon the extent to which it is 
uncovered by the suction. In another, the first nozzle passes a fixed 
amount of fuel, as the engine demands rise; this suction is communi¬ 
cated to the second nozzle and the fuel standpipe from which it draws; 
it is put into action, but varies its supply always according to demand. 
The combination of fixed and variable nozzles gives reasonably 
good vaporization at all possible speeds and under all variations of 
conditions. 

Q. What is a horizontal=outlet carburetor? 

A. The first carburetors were all connected to the engine cylin¬ 
ders through the intermediary of an inlet manifold. The latter con¬ 
nected up to the cylinder horizontal face at a number of points, and 
was carried down to a single flange for the carburetor connection. 
While the surface of this flange was horizontal, the outlet on the car¬ 
buretor, that is, the passage to this, was vertical. Consequently, 
carburetors made to fit this arrangement are said to have vertical 
outlets. With the principle of block casting, it is usual to incorporate 
the inlet manifold in the cylinder casting and have a single carburetor 
opening and place for attaching, this being a vertical face. As the 
face, or carburetor flange, is at right angles to the body of the carbu- 


GASOLINE AUTOMOBILES 


retor outlets, this brought about a horizontal outlet. A carburetor 
with this form of outlet, and intended to bolt directly upon the cylin¬ 
der casting in the manner just described, is called a horizontal- 
outlet carburetor or a horizontal carburetor. 

Q. What is a double carburetor? 

A. A double carburetor is one made for a V-type of motor in 
which a common float chamber supplies fuel to two separate and 
distinct groups of vaporizing chamber, fuel nozzle and needle, air 
inlet, etc., each half supplying one of the blocks of cylinders. That 
s to ka^, it is a doul)le car!)ui et()i, or two carburetors, if that is easier 
to understand, each one of which supplies one-half of the engine’s 
cylinders, but has nothing to do with the other half. It has been 
found that better results can be obtained in this way than in any other. 

Q. What has been the effect of vacuum feeds? 

A. The principal effect has been to raise the carburetor. For¬ 
merly, the carburetor had to be set low so the fuel could flow to it, and 
even when pressure became general, the carburetors were still set very 
low. Now, with auxiliary tank feeding, it is possible to raise the 
carburetor from two to six inches, and practically all designers have 
taken advantage of this. It makes the carburetor easier to adjust, 
easier to prime when priming is necessary, less likely to be stopped or 
clogged by road dirt or water, because it is farther away from the road 
and better protected, also, the car can go through deeper water with¬ 
out stopping. Another effect has been to produce a steadier and more 
even flow of fuel at all times and under all circumstances. In one 
way, this gave better power, in another, it benefited by giving better 
economy. 

Q. What is the vacuum feed? 

A. It is an auxiliary gasoline tank which draws the fuel from 
the main gasoline tank at the rear of the chassis (or elsewhere). It 
does this and maintains itself filled automatically, the vacuum being 
used to raise the fuel from the main tank to the auxiliary, which is 
usually about a foot higher. The tank can be placed anywhere, but 
the two usual mountings are on the inside of the bonnet, either on the 
engine or on the dash. 

Q. What other methods are there of fuel supply? 

A. The original method was by gravity, from a tank under the 
front seat. This necessitated having the carburetor so low that the 


224 


GASOLINE AUTOMOBILES 


fuel would flow to it on the steepest hill. The substitute for this was 
pressure, but this necessitated much apparatus, and the system had to 
be kept air tight, or it was useless. In this form an air pump forced 
air through a regulator into the air-tight tank, this pressure forcing 
the fuel out and to the carburetor. The latest device is similar to the 
vacuum tank but is operated by utilizing the pressure of the exhaust, 
working through a pressure-regulating valve. 

Q. Describe this exhaust=operated system? 

A. The exhaust gas pressure is cut down to a few pounds by the 
regulator, and goes thence into the rear gasoline tank. Here it 
creates pressure and forces out gasoline which must flow to the auxil¬ 
iary tank. As the tank fills, a float rises, and with it a needle, which 
closes a connection to the outside. When the tank is filled to the 
predetermined level, this arrangement opens the outside connection, 
and the exhaust gas is free to escape. As the fuel flows to the carbu¬ 
retor, the float drops and, in time, closes this opening, when the 
exhaust pressure starts the fuel flowing again. So the arrangement 
of float and outside opening keeps the auxiliary tank continually filled. 

Q. When no fuel flows, yet the tank is filled, what is the 
trouble? 

A. If the tank is full and no fuel flows, there must be an obstruc¬ 
tion in the line somewhere. Try the gasoline pipe line first for a bend 
or kink. If none is found, try the carburetor connection. Failing 
that, remove the strainer and inspect it. Then look into the float and 
float chamber, float valve and outlet to vaporizing chamber. Some 
one of these is sure to be at fault. 

Q. How can a punctured float be managed, so as to get home? 

A. Let the float sink, but oppose this sinking by means of a 
spring, carefully cut to the right length to give the same effect as if the 
float were O. K. This will carry the car to the nearest repair shop, or 
lacking that, will take it home. A punctured metal float can readily 
be soldered, but should be dried out very carefully first, this being done 
primarily to make sure there is no more gasoline inside, nor any vapor 
to condense. 

Study Questions for Home Work 

1. What are the general rules for adjusting Stromberg carbu¬ 
retors, Models L, LB, M and MB? If an entirely new setting is neces¬ 
sary on Model MB, what is the correct procedure? 


GASOLINE AUTOMOBILES 


225 


2. What is the purpose of the economizer adjustment on the 
Stromberg Model L? 

3. Tell how the main jet is replaced on the Zenith. 

4. A car equipped with a Zenith Model 0 carburetor does not 
accelerate well and slow speed running is not smooth. What is the 
trouble? W hat is the remedy when this car will not develop full 
speed? 

5. Give the method of making a slow-speed adjustment on 
the Ford car. 

0. Describe the construction of the Master carburetor 
throttle. 

7. Explain the action of the air damper on the Master car¬ 
buretor. 


S. How is the Miller carburetor adjusted for altitude? 

1). Mention in detail the process of starting adjustment of 
the Webber. 

10. How many adjustments has the Bayfield? Describe them. 

11. What is the mixture-indicating pointer on the Newcomb? 
What are its advantages? 

12. How would you adjust a hew Schebler Model “L”? 

13. What is the predominating feature of the Stewart car¬ 
buretor? 

14. How is the Johnson carburetor adjusted? 

15. What are the salient features of the Packard carburetor? 
1(3. Describe the adjustment of the Cadillac, (a) low speed, 

(b) starting, (c) high speed. 

17. Select and describe the working of a heavy fuel carburetor. 

18. Describe in detail the workings of the Carter auxiliary tank. 

19. It is desired to burn distillate in a truck. What carburetor 
would you select? 

20. What is the difference between an oxygen-adding device 


and 

the 


a regular carburetor? 

21. Describe the construction of 
Parrett air cleaner. Where are 

22. Describe the construction 


the Bennett air washer and of 
such devices necessary? 
and operation of the Toquet 


atomizer. 

23. Describe the construction and operation of the Ensign 
fuel converter. How is alcohol used in this instillment. 


226 


GASOLINE AUTOMOBILES 


24. How is vaporization obtained in the “Nitro?” How many 
adjustments are possible? 

25. What is the purpose of the flexible reeds in the Tillotson 
carburetor? How are they operated? 

26. How is a mechanical subdivision of the fuel obtained in 
the Shakespeare carburetor? How is this carburetor adjusted? 

27. Trace the fuel through the Holley “all fuel’’ carburetor. 













N 



WISCONSIN SIXTEEN-VALVE MOTOR BUILT FOR STUTZ MACHINE 












































GASOLINE AUTOMOBILES 


PART nr 


ENGINE-GROUP ELEMENTS (Continued) 

VALVES AND THEIR MECHANISM 

Importance of Valves. Probably the most important thing 
about a four-cycle gasoline engine is the valve, or, more correctly, are 
the valves, for the usual number is two per cylinder. The opening 
and closing of these control the functions of the engine; for if the valve 
does not open and allow a charge of gas to enter, how can the piston 
compress, and the ignition system fire, a charge? Similarly, if the 
exhaust valve is not opened and the burned gases allowed to escape, 
they will mingle with and dilute the fresh, incoming charge, possibly to 
the extent of making the latter into a non-combustible gas. This 
is purposely stated in this way because both methods mentioned 
have been utilized for governing the engine speed, although not to 
any great extent in automobile work. 

Summary of Valve Features. In the valves and valve mech¬ 
anisms of modern gasoline engines there have been and are impending 
more interesting changes than seem in prospect in any other portion of 
the mechanism of the modern automobile. Particularly is this the 
case with reference to the present tendency to discard the poppet 
valve with its many objectionable features. Even where there is no 
tendency toward the use of a sleeve-valve or slide-valve form of 
motor, much experimenting has been done with increasing the number 
and changing the position of the valves. 

Poppet Valves. Though the very first internal-combustion 
engines ever made were operated with slide valves, the poppet valve 
was introduced very early in the history of this art, and has reigned 
supreme in practically all types of gas and gasoline engines. 

The chief advantage of the poppet valve is its capacity for con¬ 
tinuous operation at excessively high temperatures, but since the 
cooling of engines has progressed to the status of high reliability, 





228 


GASOLINE AUTOMOBILES 


this advantage is of less importance than formerly. And the dis¬ 
advantages of poppet valves—the small openings that they afford, 
the noisy and hammering action they involve, their tendency to leak 
and in other ways give out, and the necessity for frequently regrinding 
them—are objections so serious that it is no wonder the prospect of 
their elimination is so widely welcomed. 

About the only recent improvement that has been made in 
poppet valves is in the quality of material used in them. Many 
valves now used have cast-iron and nickel heads, which offer a max¬ 
imum resistance to warping from the heat to which they are subjected. 
These are fitted with carbon-steel stems, which are superior in their 
wearing qualities. More use has been made recently of tungsten 
as a material for valves. Steel containing this is even harder than 
nickel steel, and experiments have shown that it does not warp as 
much. In practice, the objection found to cast-iron heads was that 
the fastenings to the carbon-steel stem were not sufficiently strong 
to withstand the constant pulling and pushing to which a valve was 
subjected. As a result they separated, causing trouble. 

In the operation of poppet valves, the cams become an important 
factor. ~ These are the parts which, in revolving, raise the valves so 
that they open at the proper time. In addition, the cams are so shaped 
as to hold the valves open for just the right length of time and allow 
them to close, through the medium of the valve-spring pressure, at 
the proper point in the cycle. The importance of this can be seen, 
if we consider that opening the slightest fraction of a second too late 
will reduce the amount of the charge very much, and thus lessen the 
power developed by the motor. 

Enclosures. The use of casings to enclose the valve stems, 
springs, and push rods, so as to keep these elements from exposure 
to dirt, and at the same time silence, in a large degree, the noise they 
make, is also becoming usual. 

Many excellent examples of this may be seen in modern motors. 
The whole side of the motor where the valve mechanism is located is 
covered with a long removable plate, keeping in noise and lubricant 
and keeping out dirt. Usually, however, on a six-cylinder motor the 
valve enclosure is made in two parts, one half enclosing the mechanism 
of the valves in the first three cylinders, the other half, those in the 
last three. This is, of course, the preferred construction on those six- 


GASOLINE AUTOMOBILES 


229 


cylinder engines which have the cylinders cast in threes, instead of in 
a block, as the one referred to. On some motors where this construc¬ 
tion has not found favor, the designers have followed the plan of 
enclosing the individual valve mechanisms. While more expensive, 
this method is equally as efficient. On the other hand, it adds to the 
parts, and the whole modern tendency has been to reduce the number 
of parts. 

Sleeve Valves. This type of valve, while not at all new, has only 
within the past few years come into considerable prominence, chiefly 
as a result of the truly remarkable performances of the Knight motor, 
which is equipped with the most advanced examples of this type 
of valve. 

Contrary to past opinion, it has been conclusively demonstrated 
that sleeve valves do not, to any perceptible degree, increase the 
tendency of a motor to overheat, nor do they wear at any very meas¬ 
urable rate. They afford, moreover, in the best constructions, a much 
higher thermal and mechanical efficiency than it is possible to secure 
from the average poppet-valve motor, this improvement being due to 
the better-shaped combustion chamber that can be used and the 
greater areas of valve opening, which facilitate the ingress and egress 
of the charges. 

Another advantage in favor of the sleeve valve is that its timing 
is permanent and unchangeable and does not alter materially with 
wear. Not the least of the merits of the sleeve valve is found in 
the fact that it lends itself to positive operation by eccentric mech¬ 
anisms, which are in every way greatly superior to the non-positive 
cam mechanisms universally used to actuate poppet valves. 

A very good example of this latest type of Knight motor is 
illustrated in Fig. 149, showing the intake side of the Moline-Knight 
four-cylinder motor. 

Sliding Valves. Sliding valves of other than the sleeve type, 
embracing a considerable variety of piston valves and valves similar to 
those employed in steam engines, have not found as much favor with 
designers of automobile engines as have other types herein referred to. 

One exception is the successful use of a “split-ring” valve sliding 
up and down in the cylinder head just above the piston, which has 
found successful application in a few motors recently built by the 
Renault Company, of France. 


230 


GASOLINE AUTOMOBILES 


Rotating Valves. A number of engines with rotating valves have 
been built from time to time, but none of these seem to have survived 
the test of time, for not one which was in evidence two years ago is 
being made now. A case in point is the Speedwell car with the Mead 
rotating-valve motor. The motor was excellent but is no longer made. 

Half-Time Shafts. For the actuation of the valve mechanism 
of any four-cycle motor, it is necessary to have a shaft (or in the case 



Fig. 149. Intake Side of Moline-Knight 50-Horsepower Motor 
Courtesy of Moline Automobile Company, East Moline, Illinois 


of rotary valves, to run the valve itself as a shaft) turning at one-half 
the speed of the crankshaft through a two-to-one gear ratio. 

Ordinarily the half-time shaft is the camshaft, but in motors 
of the Knight type it is, of course, an eccentric shaft. Camshafts, par¬ 
ticularly, call for good workmanship and high-grade materials, as well 
as sound design, since the constant pounding of the valve stems 
or push rods on the cams is a prolific source of trouble, if anything 
but the soundest of sound construction be employed. 















GASOLINE AUTOMOBILES 


231 


The most important recent innovation in this detail of auto¬ 
mobile mechanism is the driving of half-time shafts by silent chains 
m place of the long-used gearing of spur and helical type. By this 
improvement the noise of the gears is eliminated. 

A typical silent-chain installation, driving half-time shaft and 
other shafts as well, is seen in Fig. 150, which presents the King eiglit- 



Fig. 150. Front of King Eight with Cover Removed to Show Use of Silent Chain 
Courtesy of King Motor Car Company, Detroit, Michigan 

cylinder motor with the chain cover removed. These occupy the 
compartment formerly called the gear case, or gear cover, when all 
driving was done by gears. Here it will be noted that there are two 
sprockets on the crankshaft; one driving the camshaft through the 
medium of a third sprocket which serves a double purpose, as a chain 







232 


GASOLINE AUTOMOBILES 


tightener and as a drive for the pressure oil pump; while the other 
sprocket, through a second silent chain, drives the electric generator 
at the right, no tightener being needed as the generator can be 
moved sufficiently to care for this. 

In the Cadillac motor, shown in Fig. 2, Part I, a pair of gears is 
used, one driving the camshaft from the crankshaft, while the other 
drives the auxiliary shaft from the camshaft. In the American form 
of Knight sliding sleeve-valve motors, shown in Fig. 149, a pair of 
silent chains is used for the eccentric shaft on one side and the electric 
generator on the other. These are driven from a pair of sprockets 
set side by side on an extension of the crankshaft. 

A point that should be brought out in connection with silent- 
chain camshaft driving is that the use of the chain allows the shafts 
to be placed anywhere desired and thus, to a certain extent, frees 
the designer from the former restriction of a two-to-one reduction 
ratio in the gears, which rather fixed the size and, consequently, the 
position of the gears. This restriction had an influence also upon 
cylinder design, as the center of the camshaft fixed the center of all the 
valves, that is, their distance from the center line of the motor. 

DETAILS OF POPPET-VALVE GEARS 
Cams 

Friction. Granting the necessity for proper means to regulate 
the inflow and outgo of the charge and consequent products of 
combustion, as exemplified by the valves, the next most important 
part is the one which controls the movement of the valve, and is, 
therefore, essential to the success of the latter. This is what is known 
as a cam and in the usual case amounts to an extension of, or pro¬ 
jection from, the so-called camshaft. In as much as the valve func¬ 
tions only come into play upon every other stroke of the crankshaft, 
this camshaft is gear-driven from the crankshaft, so as to rotate at 
half the speed of the latter. This is very simply effected by having 
the cam gear twice as large as the crankshaft gear. As the same valve 
is never used for both the inlet and the exhaust, so the cams are seldom 
made to do more than the one thing, namely, operate one set of the 
valves. From this has grown the custom of referring to them accord¬ 
ing to the function of the valve which they operate—inlet cam, 
exhaust cam, etc. 


GASOLINE AUTOMOBILES 


233 


TABLE I * 


Timing Regulation of a Number of Prominent French Motors 


Nos 


Lead 
of Ex¬ 
haust 
Open¬ 
ing 

1 

Ours. 

55° 

2 

Charron—20/30 h.p., 1908.. . 

44° 

3 

Rossel—40 h.p., 4 cylinders.. . 

38° 

4 

Gregoire—10/14 h.p., 4 cylinders, 



1908. 

53° 

5 

Motobloc—24 h.p., 100/120, 


190S. 

45° 

6 

Panhard-Levassor. 

45° 

7 

Hotchkiss—4 cylinders, 95/100. . 

44° 

8 

Cottin-Desgouttes—18/22 h.p.. 

46° 

9 

Brouhot—12 h.p., 4 cylinders, 



75/110. 

45° 

10 

Cornilleau -Ste. - Beuve — 20/30 



h.p., 1908. . 

56° 

11 

Mutel—40 h.p., 1908. 

62° 

12 

Berliet—22 h.p., 1908. 

48° 

13 

Peugeot (Paris) —18/24 h.p., 



1908. 

58° 

14 

Labor—20/30 h.p. 

51°20' 

15 

Luc Court. 

45° 

16 

Brasier. 

45° 

17 

Peugeot ( Beaulieu ) . 

51°30' 

18 

Aster—9 h.p., 105/120 .. . 

o 

O 

19 

Rochet-Schneider—24 h.p., 100/- 



120. 

0 

O 

20 

De Dion-Bouton—12 h.p., 4 cylin- 


ders, 1908 . 

45° 

21 

Eudelin. 

36° 

22 

Farcot—14 h.p., 80/100. 

36° 

23 

C henard-W alcker. 

36° 

24 

Darracq—10/12 h.p., 100/120.. . 

48° 

25 

Aries—14/18 h.p. 

58° 

26 

Vinot-Deguingand — 12/16 h.p., 



80/110. 

30° 

27 

Sultan—9/12 h.p., 4 cylinders, 



75/110. 

58° 

28 

Renault—8 h.p., 2 cylinders. . . 

32° 

29 

Unic—20 h.p., 75/110. 

53° 

30 

Sizaire et Naudin—15 h.p., 120/- 



110. 

44° 

31 

Larrad Device. 

52° 


Average. 

46°20' 


Lag of 
Inlet 
Clos¬ 
ing 

Igmt. 

Ad¬ 

vance 

Lag of 
Exh. 
Clos¬ 
ing. 

Lag of 
Inlet 
Open¬ 
ing 

Rela¬ 
tion of 
Conn. 
Rod to 
Radius 
Crank 

R.p.m. 
at Full 
Power 

20° 

var. 

0° 

15° 

4 

.76 

1 

000 

0° 

— 

0° 

1° 

4 

.55 

1 

100 

23° 

— 

0° 

2° 

4 

.29 

1 

100 

0° 

— 

0° 

5° 

4 

.18 

l 

200 

10° 

— 

5° 

10° 

4 

. 75 

1 

200 

40° 

■— 

0° 

0° 

4 

.5 

1 

200 

33° 

— 

10° 

17° 

4 

.27 

1 

300 

30° 

38° 

8° 

15° 

4 

.15 

1 

300 

45° 

30° 

0° 

20° 

5 


1 

300 

20° 

43° 

6° 

20° 

4 

.62 

1 

300 

21° 

var. 

28° 

26° 

4 

.4 

1 

300 

3S° 

— 

9° 

17° 

4 

.5 

1 

300 

18° 

38° 

0° 

10° 

4 

76 

1 

300 

0° 

var. 

0° 

0° 

4 

18 



0° 

— 

15° 

30° 

4 

25 



25° 

34° 

0° 

7° 

4 

5 

1 

350 

58° 

31° 

20° 

15° 

4 

78 

1 

400 

40° 

var. 

0° 

0° 

4 

3 

1 

400 

20° 

20° 

0° 

20° 

4 

75 

1 

400 

45° 

30° 

0° 

0° 

4 

7 

1 

400 

20° 

var. 

4° 

8° 

4 

3 

1 

450 

10° 

— 

2° 

6° 

4 


1 

500 

36° 

— 

0° 

0° 

5 

25 

1 

500 

30° 

21° 

0° 

0° 

4 

5 

1 

500 

44° 

20° 

13° 

18° 

4 

91 

1 

500 

15° 

27° 

0° 

15° 

4. 

54 

1 

500 

42° 

32° 

14° 

22° 

4. 

55 

1 

600 

26° 

33°30' 

10° 

23°30' 

4. 

33 

1 

600 

40° 

30° 

10° 

34° 

4. 

5 

1 

650 

37° 

var. 

0° 

15° 

5. 

25 

1 

700 

17° 

— 

22° 

17° 





26°15' 


5°40' 

8°6' 




* The motors are arranged in the order of their increasing speeds. The angles are figured 
in degrees, counting from the nearest dead center. “Var.” means that the point of ignition may 
be advanced or retarded by the driver. 


In laving out or designing a set of cams for a gasoline engine, 
such as is used on an automobile, it is first necessary to decide upon 
the exact cycle upon which to operate the engine. By this is meant 
the exact length of time, as referred to the stroke, in which the valve 
action will take place. Upon this subject, designers all over the 
world differ, and no wonder, as this cycle can but be judged by 
results, for it is impossible to watch it as it transpires. Deductions 
differ, therefore, as to what happens and, consequently, as to the 
effect of various angles of beginning and ending of the valve actions. 

























































234 


GASOLINE AUTOMOBILES 


TABLE II 

Timing Regulation on a Number of Prominent American Motors 


Nos. 


Lag of 
Inlet 
Opening 

Lag of 
Inlet 
Closing 

Lead of 
Exhaust 
Opening 

Lag of 
Exhaust 
Closing 

1 

Abbott 34-40 ... 

11° 30' 

44° 12' 

45° 4S' 

11° 30' 

2 

Abbott 44/50 . 

17° 53' 

29° 25' 

42° 36' 

8° 20' 

3 

Abbott Belle Isle. 

10° 00' 

20° 00' 

40° 00' 

2° 30' 

4 

Allen 40. 

15° 00' 

40° 00' 

45° 00' 

10° 00' 

5 

Cadillac 1914. 

14° 20' 

38° 26' 

31° 34' 

17° 00'* 

6 

Cameron 1914. 

5° 00' 

20° 00' 

50° 00' 

10° 00' 

7 

Corbitt D, E, and F. 

11° 00' 

35° 00' 

45° 00' 

3° 00' 

8 

Chalmers. 

12° 00' 

33° 00' 

55° 00' 

12° 00' 

9 

Crescent. 

20° 00' 

45° 00' 

55° 00' 

15° 00' 

10 

Chandler Six. 

14° 00' 

39° 00' 

49° 30' 

12° 00' 

11 

Crane 4. 


35° 00' 

50° 00' 

10° 00' 

12 

Correja. 

10° 00' 

35° 00' 

44° 00' 

5° 00' 

13 

Chevrolet C. 

13° 00' 

49° 00' 

47° 00' 

9° 00' 

14 

Case 40. 

13° 00' 

30° 00' 

50° 00' 

13° 00' 

15 

Cunningham. 

15° 00' 

15° 00' 

40° 00' 

12° 00' 

16 

De Soto Six. 

10° 00' 

25° 00' 

38° 00' 

8° 00' 

17 

Franklin V-4. 

8° 00' 

33° 00' 

51° 30' 

17° 00' 

18 

Great Southern. 

14° 00' 

25° 00' 

35° 00' 

10° 00' 

19 

Haynes, 26, 27, and 28 . 

5° 00' 

35° 00' 

47° 00' 

2° 00'f 

20 

Howard 6-D. 

10° 00' 

28° 00' 

40° 00' 

2° 30' 

21 

Hupmobile 32. 

21° 00' 

28° 00' 

46° 00' 

16° 00' 

22 

Jackson Olympic, Majestic, and Sultanic 

15° 00' 

38° 00' 

45° 00' 

10° 00' 

23 

Jeffery 6-96 and 4-93. 

18° 00' 

46° 00' 

47° 00' 

15° 00' 

24 

King B... 

9° 44' 

30° 38' 

32° 10' 

5° 00' 

25 

Krit M. 

12° 00' 

28° 00' 

39° 00' 

2° 00' 

26 

Lewis Six. 

15° 00' 

30° 00' 

45° 00' 

5° 00' 

27 

Locomobile R3 and M4. 

Dead Center 

46° 22' 

50° 52' 

16° 27' 

28 

McFarlan 6-T. 

10° 00' 

36° 00' 

43° 30' 

10° 00' 

29 

Maxwell 4—35. 

5° 00' 

40° 00' 

35° 00' 

Dead Center 

30 

Maxwell 4-25. 

6° 00' 

32° 00' 

43° 00' 

6° 00' 

31 

Moon Six 50. 

10° 00' 

28° 00' 

40° 00' 

2° 30' 

32 

Moon Four 42. 

14° 00' 

24° 00' 

31° 00' 

21° 00' 

33 

Marathon Winner, Runner, Champion. . 

12° 00' 

45° 00' 

46° 00' 

7° 00' 

34 

Moyer E and G. . . 

8° 00' 

40° 00' 

45° 00' 

10° 00' 

35 

Norwalk 6 C and 6-D. 

6° 00' 

40° 00' 

45° 00' 

5° 00't 

36 

Oldsmobile 54. 

15° 00' 

38° 00' 

45° 00' 

10° 00' 

37 

Paige 25. 

9° 40' 

32° 25' 

40° 30' 

12° 00' 

38 

Paige 36. 

9° 40' 

32° 30' 

41° 50' 

11° 40' 

39 

Palmer-Singer Brighton Six L. 

6° 00' 

40° 00' 

45° 00' 

5° 00' 

40 

Paterson 32 and 33. 

15° 00' 

38° 00' 

45° 00' 

10° 00' 

41 

Pathfinder 4. 

11° 30' 

44° 12' 

45° 48' 

11° 30' 

42 

Pathfinder Big and Little Six. 

10° 00' 

28° 00' 

40° 00' 

2° 30' 

43 

Pratt 50. 

12° 00' 

45° 00' 

45° 00' 

10° 00' 

44 

Reo the 12th. 

18° 00' 

36° 00' 

53° 30' 

14° 00' 

45 

Republic E. 

15° 00' 

30° 00' 

45° 00' 

10° 00' 

46 

S. & M. 

10° 00' 

28° 00' 

40° 00' 

2° 30' 

47 

Selden 49. 

13° 00' 

26° 30' 

48° 30' 

7° 30' 

48 

Simplex 50. 

13° 10' 

34° 40' 

57° 30' 

15° 40' 

49 

Simplex 38. 

10° 20' 

31° 40' 

54° 20' 

7° 50' 

50 

Spaulding T. 

5° 00' 

45° 00' 

55° 00' 

5° 00' 

51 

Speedwell ABC. 

10° 00' 

28° 00' 

40° 00' 

2° 30' 

52 

Touraine 12. 

3° 00' 

40° 00' 

43° 00' 

3° 00' 

53 

Velie 9-45, 6-40, 9-5, 9-4, 9-2, 6-5, anc 






6-4. 

■7° 00' 

36° 00' 

43° 00' 

12° 00' 

54 

Velie 11-35. 

5° 00' 

31° 00' 

39° 00' 

13° 00' 

55 

Vulcan. 

15° 00' 

30° 00' 

45° 00' 

10° 00' 

56 

Zimmerman B-6. 

10° 00' 

25° 00' 

38° 00' 

8° 00' 

1_ 

Average. 

10° 48' 

35° 7' 

50° 10' 

9° 20' 


* Some Cadillacs have the inlet opening at 4° 20' past the top center and the exhaust 
closing 7° 00' past. 

t The Haynes 28 has the exhaust opening 37° 00' before the lower center instead of 47° 00'. 

t Norwalk 6-D has the inlet opening at 8° 00' instead of 6° 00', and the exhaust closing 
on the upper dead center instead of at 5° 00' past. 

Tables of Valve Settings. Table I, showing the valve settings 
used by the foremost French car designers, is here given as a basis 























































































GASOLINE AUTOMOBILES 


235 


of comparison with the valve data of American types, Table II. The 
valve timing for American cars as produced in 1913 and 1914 is 
given in Table II, while Table I was compiled in 1908; a comparison 
which indicates in a measure the advance in the past five oi six years. 
In studying these tables, it should be borne in mind that all angles are 
spoken of in terms of the crankshaft and are usually referred to the 
two dead centers, commonly spoken of as the upper dead center and 
the lower dead center. 

In Tables I and II, it will be noted that in so far as maximum 
openings were concerned there has been little change. The earliest 
exhaust opening of 1908 was Mutel at 62°; the earliest American 
exhaust opening of the present is Simplex 50 at 57° 30'. The former 
closed at 28°, while the latter closed at 15° 40', thus giving the French 
motor a total exhaust opening of 270°, while the American has but 
253° 10'. Simplex is not a representative American car, however; 
it is a special model with racing characteristics, and is built only to 
order. Crescent and Reo are the real leaders. 

With reference to inlet valves, the situation is somewhat similar, 
the largest foreign lag in opening is the Unic with 34°; while the 
largest American opening lag is the Ilupmobile with 21°. In closing, 
the highest figure reached by the foreign product is 58° by Peugeot, 
and on this side, 49° by Chevrolet. The former shows also the 
greatest total, 254°; but the largest American total is that of Crescent 
with 205°. 


These, however, represent the extreme cases, and the averages 
tell a different story. The average foreign inlet opening (total) in 
1908 was 232°, while the average American inlet opening is now 
239.3°. Similarly, with the exhaust total opening, the average foreign 
figure then was 214.5°, the average American figure is now 226.2°. 

It is unfortunate that the speed at full power output of the 
American motors is not available also, as that would allow an even 
more interesting comparison of the two tables. In 1 able I, it will 
be noted that the motors are arranged in the order of their maximum 
speeds. Were the American speed figures available, it would show 
for one thing whether speeds of today are, as claimed, so much 
higher than formerly and also, what is more to the point, what valve 
setting gives the highest speed. Referring to Table I, it will be seen 
that Unic with the greatest lag of inlet opening and the greatest 


236 


GASOLINE AUTOMOBILES 


total inlet opening is next to the highest in speed, whereas the others 
having high lag figures are all down among the moderate speeds. 

Now, if the average of the numerous examples of good practice 
be taken, it is not a hard matter to explain the form of the cam and 
its derivation. The height of the upper surface of the highest part 
of the cam above the surface upon which the valve-actuating device 
normallv rests determines the lift of the valve, which is the name 
given to the amount it is opened or lifted. This is not really the lift 
of the valve because of the fact that in all valve-operating systems 
there is a certain amount of clearance between the lower end of the 
valve stem and the upper end of the valve lifter mechanism. This 
clearance must be taken up by the cam before the valve itself is 
actually lifted, so, to obtain the true lift, the amount of the clearance 
is subtracted from the lift as determined by the earn height. Know¬ 
ing this, designers usually predetermine the clearance and allow 
for it in the height of the cams. 

Typical Valve Actions. Figs. 151 and 152 illustrate the complete 
valve action very well; the former, that of the Locomobile Company 
of America, Bridgeport, Connecticut, showing the form in which the 
cam works against a roller in the bottom of the push rod. This works 
upward in the push-rod guide and has a dirt excluding arrangement 
at the top. The top of the push rod bears against the bottom of the 
valve stem with an adjustable hardened screw forming the contact. 
The valve is held down on its seat in the cylinder by means of a strong 
spring, which the upward movement of the push rod opposes. The 
valve is guided in and has its bearing in the valve guide, which is 
made long to give large bearing surface. As the Locomobile motor 
is of the T-head type, the exhaust and inlet valves are on opposite 
sides of the cylinders and are operated by separate camshafts. The 
valve mechanism is completely enclosed. 

The second figure shows the valve action used on Haynes cars, 
made by the Haynes Automobile Company, Kokomo, Indiana. 
The difference is in the elimination of the roller at the bottom of the 
push rod which forms the poir' of contact with the cam. In this 
form, a flat hardened surface makes the push rod more simple and 
reduces the number of parts. It has been said against this form 
that the cam scrapes across the push-rod face and thus wears it, 
but in actual use it has been found that the push rod rotates and 





GASOLINE AUTOMOBILES 


237 


t 


in this way the wear is distributed over the whole flat face, which 
in this construction can be made much larger than can the face of 
the roller. The push rods are of the “mushroom 11 type and are 



Fig. 151. Complete Valve 
Motion with Roller Push Rod 

Courtesy of Locomobile Company 
of America, Bridgeport, 
Connecticut 


Fig. 152. Complete Valve Motion 
wi hout Roller in Push Rod 

Courtesy of Haynes Automobile 
Company, Kokomo, Indiana 


made of nickel steel. The push-rod adjustments are completely 
enclosed but may be readily reached without disturbing any other 
unit. They may be removed and replaced without removing the 
valve springs or valves. 



























































































































GASOLINE AUTOMOBILES 


2)38 


Neither of these systems is in decided favor, designers being 
about equally divided between them. 

The construction and operation of the cam mechanism is the 
same whether used in connection with an exhaust or an inlet valve; 
as the same line of reasoning and the same method of procedure, 
in both cases, would lead to the same results. 

It has many times been tried and still more often urged that 
the straight surface of the side of the cam is not conducive to the 
best results, because of the fact that when the first straight portion 
of the cam surface strikes the cam roller it does so with so much 
force that it tends to wear the latter in that direction. As for the 
receding face, it has been urged that the ordinary closing of the 
valve is too slow and that the straight surface can be altered so as to 
allow of speeding up the downward movement of the valve. This idea 

works out into a curve; 
the back of the surface is 
hollowed out so that as 
soon as the cam roller 
passes the center it drops 
vertically, owing to the 
tension of the spring. 
This method has been 
tried, but without suc¬ 
cess. 

What Good Modern 
Practice Shows. A more 
modern way, which is 
fast becoming universal, is to use straight sides for the cams and 
take advantage of rapid closing in another way, the benefits of 
which more than offset the benefits of the old way and have no corre¬ 
sponding disadvantages. In the ordinary automobile engine running 
at 1000 revolutions per minute, the gases are traveling into the cylin¬ 
der at the rate of 5000 to 6000 feet per minute, and traveling out at 
from 7000 to 10,000 feet per minute. At this tremendous speed, the 
gas inertia is very high, and experiments go to show that the gases by 
means of this inertia will continue to force their way into the cylinder 
even against the return motion of the piston. So it is now common 
practice to hold the inlet valve open about 30 degrees on the upstroke 



Fig. 153. 


Power Curve of an American Engine with 
Superior Cams and Balancing 


















































































































































































































GASOLINE AUTOMOBILES 


239 




of the piston, which results in a much larger piston charge. The same 
practice is carried out with the exhaust, but as the pressure is higher, 
so large an angle is not necessary. These actions take place on 
the back flat side of the earn surface and have given to the high¬ 
speed automobile engine a larger charge and a more complete 
scavenging effect, resulting in more power and speed from the same 
size of cylinder. 

, As proof of this statement, the power curve of an engine of 
but 3§-inch diameter of cylinder is shown in Fig. 153. This size of 
six-cylinder engine would be rated by any formula at about 29 
horsepower at the maximum speed, and a commercially obtainable 
type in this size would doubtless be guaranteed to deliver between 
20 and 25 horsepower. This engine, which is not built for racing 
purposes, displays a power curve which continuously rises; a speed at 
which it would turn downward has not been obtainable in the tests. 
This curve shows also that the maximum power obtained was over 
80, which is nearly three times the power of the ordinary engine of 
this same size. This result is ascribable to superior valves and 
superior attention to the valve angles as governed by the cams. 

Number of Valves per Cylinder. Three Valves per Cylinder. 
When it was stated that but two valves per cylinder were ordi¬ 
narily used, with one cam for each, the majority case was spoken of. 
But, as it is a fact that there are other cases which differ from this, 
it would not be fair to close the subject without mentioning them. 
The most prominent advocate of air cooling in this country and the 
world, the H. H. Franklin Manufacturing Company, used three 
valves, and consequently three cams, per cylinder. These three were 
the ordinary inlet; the usual exhaust; and the additional auxiliary 
exhaust. By re-designing later, this complication was avoided and 
the third valve eliminated. 

The Wisconsin Motor Company has developed another motor 
with four valves per cylinder and, after a notable racing success, 
has placed it upon the market. Any maker desiring to do so, may 
purchase this and incorporate it in his chassis. This emphasizes the 
distance which the sixteen-valve four-cylinder motor has progressed 
in the space of a year or so. A section through this motor, both side 
elevation and end view, showing all the details of the construction, 
is shown in Fig. 154. A full view of the intake side is given in Fig. 155. 


.-y 



240 


GASOLINE AUTOMOBILES 

























































































































































































































































GASOLINE AUTOMOBILES 


241 



Fig. 155. View of Intake Side of Sixteen-Valve Motor 
Courtesy of Wisconsin Motor Company, Milwaukee, Wisconsin 

of the cylinder is greatly increased in this way, giving more power and 
speed from the same size of cylinders, so much more, it is claimed, as to 
make a four-cylinder engine with sixteen valves the equal of a six- 
cylinder with but twelve valves. Another big advantage claimed for 
the smaller lighter valves of this construction is that very much lighter 
valve springs can be used. This advantage was discovered by using 
sixteen valves on four-cylinder racing engine where the compression 




l 1 our Valves per Cylinder . The very latest practice in the way of 
multiple valves is the use of four valves per cylinder—two inlets and 
two exhausts. There are a number of reasons why this construction 
is a good one. It is said that the area through which the gases enter 
and leave the cylinder can be made greater, thus giving the same or 
greater supply of gas more quickly and, after using it, ejecting it with 
the same or a greater volume more quickly. The volumetric efficiencv 








242 


GASOLINE AUTOMOBILES 


and other pressures were enormous. The valve springs for the ordi¬ 
nary eight-valve engine had to be very stiff and, consequently, gave 
much cam trouble. The stiff springs dug out the sides of the cams very 
rapidly and also failed rapidly themselves. With the lighter springs 
which can be used with sixteen valves, these troubles are eliminated. 

In the 39 cars starting in the last French Grand Prix, all but 
three were four-cylinder forms. Of these 36, two had sleeve valves 
and three had the usual number of valves, but the other 31 all had 
sixteen overhead valves. These were about equally divided in 
respect to camshafts, 17 having but one, 14 having two. In the 
recently developed Stutz motor, made by the Wisconsin Motor Com¬ 
pany, the engine has the outward appearance of any other T-head 
form, for the use of double the usual number of valves does not change 
the exterior at all. 

One Cam per Two Valves Influences the Shape. A case in which 
the cam does differ is that of the use of two overhead valves operated 

by a single camshaft, Fig. 156. This 
practice originated with the F. I. A.T. 
Company, which brought it out for 
racing use only, where it, was particu¬ 
larly useful in that it halved the 
weight of the camshaft, as well as 
saved much weight in push rods, etc. 
Later, this was taken up by other 
firms for regular use, although the 
company which first brought it out 
has never done so. 

In this country it has been tried 
by many makers. The work of open¬ 
ing the extra valve is done by a 
spring, i.e., a depression in the back 
of the cam allows a strong spring to 
pull the push rod down, by which process the valve stem is depressed 
and the valve opened. 

The V-type of motor has made considerable difference in valve 
motions; for one thing, bringing into use valves set at an angle with 
the vertical, a practice previously considered very bad because the 
weight of the valve adds to the tendency to wear the valve and seat on 



Fig. 156. Overhead Valve Motion with 
Followers Working Directly on Valve 
Stems and Having no Push Rods 

Courtesy of Chalmers Motor Company, 
Detroit, Michigan 




































GASOLINE AUTOMOB 1LES 


243 


the low side. In the form shown in Fig. 157, the eight-cylinder motor 
used in the Briscoe .38, made by the Briscoe Motor Company, Jackson, 
Michigan, there are no unusual features. The single camshaft with 
lb cams is centrally placed in the middle of the V and operates the 
push rods, inclined outward, parallel to their respective groups of 
cylinders. A rocker arm, or follower, is used at the cylinder heads to 
transfer this up-and-down motion to the valves which are set in 
the center of the cylinder heads and are thus parallel to the push rods. 



Fig. 157. Section through Briscoe Eight, Showing Camshaft Arrangement 


In the majority of V-type motors, both eights and twelves, the 
valves are in side pockets; the cylinders are of the L-type, and thus 
there is no radical innovation except the inclined push rods and valve 
systems. In a few of these motors, however, a follower is used 
between the cams and the push rods because of other structural reasons. 

When any kind of a cam follower differing from the usual direct- 
lift push rod is used, this may or may not affect the shape of the cam. 
Usually it does not, so that the shape does not have to be taken into 
account. Ordinarily these followers are used to prevent side thrust 
on the push-rod guide, the follower itself taking all the thrust and 































































244 


GASOLINE AUTOMOBII.ES 


being so designed as to be readily removable or adjustable, to take 
care of this. In cases where this does not obtain, the object usually 
sought is the removal of noise. The two objects may be combined, as 

in the case shown in Fig. 158. This 
represents an enlarged view of the 
cam mechanism of the famous one- 
cylinder French car, Peugeot. It 
will be clear that the action is that 
of one cam operating both tire 
exhaust and the inlet valves through 
the medium of a pair of levers, upon 
which the cam works alternately. 

A cam follower of somewhat 
different form, but one achieving the 
same results, will be noted in the 
Cadillac eight-cylinder motor, shown 
in Fig. 164, where attention has been called to these, and also in the 
Chalmers six-cylinder motor with overhead valves, shown in Fig. 156. 

Difficulties in Making Cams. There was a time when the pro¬ 
duction of a good, accurate camshaft was a big job in any machine 
shop, well-equipped or otherwise, and represented the expenditure of 
much money in jigs, tools, and fixtures. Now, however, the machine- 
tool builder has come to the rescue of the automobile manufacturer, 
and special tools have made the work easy. So it was with the pro¬ 
duction of the shaft with integral cams; this used to be a big 



Fig. 158. Cam Mechanism of Peugeot 
Single-Cylinder Engine 



Fig. 159. Cams Integral with Shaft—Milling Machine Job 



Fig. 160. Another Camshaft with Integral Cams 


undertaking, but today special machinery has made it an easy matter. 
The illustrations, Figs. 159 and 160, show some of the product of a 
cam milling machine. This is now the favbred way of putting out 
engines, for the integral cams and shaft have the advantage of much 
lower first cost and, with proper hardening, will last fully as long as 
those made by mounting the separate cams directly on the shaft. 









































GASOLINE AUTOMOBILES 


245 


Grinding Increases Accuracy. An even later improvement in 
the way of a machine for producing earns on an integral shaft is 
the grinding machine which has been developed for this purpose. 
This works to what is called a master camshaft, that is, a larger 
size of shaft which has been very accurately finished. This master 
shaft is placed in the grinding machine, the construction of which 
is such that the grinding wheel follows the contour of the very accu¬ 
rate master shaft and produces a duplicate of it, only reduced in size, 
a reducing motion being used between master shaft and grinder- 
wheel shaft. 

The result of this arrangement is a machine which is almost 
human in its action, for it moves outward for the high points on the 
cams and inward for the low 
spots on the shaft. Moreover, it 
has the further advantage that 
all shafts turned .out are abso¬ 
lutely alike and thus accurately 
interchangeable. It allows also 
of another arrangement of the 
work, the drop forging of the 
shafts within a few thousandths 
of an inch in size; the surface of 

t 

skin is easily ground off in one 
operation, then the hardening is 
done, and the final grinding to 
size is quickly accomplished. In this way, the shafts may be 
produced more cheaply than was formerly the case and have, in 
addition, the merits brought out above, namely, greater accuracy, 
superior interchangeability, and quicker production. 

The same process is applicable to, and is used for, othei paits of 
the modern motor car; thus crankshafts are ground, pump and mag¬ 
neto shafts are finished by grinding, and many other applications of 
this process are utilized. The process can be extended indefinitely, 
the only drawback being that a master shaft is very expensive. 

Old Way Required More Accurate Inspection. With the old 
method of making the cams and shaft separate, the amount of 
inspection work was very great and represented a large total expense 
in the cost of the car. Thus, it was necessary to prove up every cam 



Fig. 161. Useful Form of Gage for Separate Cams 


























240 


GASOLINE AUTOMOBILES 


separately, as well as every shall, and, later, the earns and shaft 
assembled. One of the forms of gages used for inspecting cams 
is shown in Fig. 161. It is in two pieces, dovetailed together. This 
allows of the testing of many shapes of cam with but one base piece 
and a number of upper, or profile, pieces equal to the number of differ¬ 
ent earns to be tested. To test, the cam is slipped into the opening, 
and if small, the set screw forces it up into the formed part of the 
gage, showing its deficiencies; while if large, it will not enter the form. 

Valve Timing 

This increase of speed without material alteration in the engine is 
what every repair man aims to get when he goes over the timing of the 

motor. Valve timing has been 
called an art, but it is not; it is 
only the application of common 
sense and the known valve dia¬ 
gram to the motor in an attempt 
to get the best all-around results. 
These, as might be expected, are 
a compromise, and that repair 
man does the best timing, who 
realizes this and, instead of 
attempting the impossible, sim¬ 
ply produces the most desirable 
a 11-around compromise. 

Fly wheel Markings. Nearly 
all motors now have the timing 
marked upon the rim or face of the flywheel, so that it is unnecessary 
to bother with the crankshaft and pistons. This has been found by 
experience to be the best and handiest way, for the flywheel is gen¬ 
erally accessible without removing many other parts. The same is 
true with the valves. This is not the case with pistons and crank¬ 
shaft; moreover, with these it is difficult to determine the exact upper 
and lower dead centers, and still more difficult to work to angles. 

To use these settings marked on the flywheel, a stationary pointer 
on the upper surface of the crankcase hangs over the flywheel surface 
as closely as possible and indicates the reading. The flywheel is 
turned by hand or by means of the crank at the front of the engine 



Fig. 102. Valve-Timing Diagram for 1915 
Four-Cylinder Overland Motor 

Courtesy of Willys-Overland Company, 
Toledo, Ohio 












GASOLINE AUTOMOBILES 


247 


until a mark or the desired mark is brought up to the pointer. Thus, 
the cylinders are marked from front to back always, that nearest the 
radiator being 1, the next 2, then 3, and the last, in the case of a 
four-cylinder motor, 4. In a six-cylinder motor the method is the 
same with the addition of two cylinders, the one nearest the dash 
being, of course, 6. The flywheel sometimes has the positions marked 
on its surface, as well as the valve operations. Referring to Fig. 162, 
this shows the valve-timing diagram of the four-cylinder Over¬ 
land for 1915. Notice in this that none of the valve operations begin 
or end on a dead center point so that even if the centers are marked 
on the flywheel (as they are in this case) this is of little benefit except 
as will be pointed out. The marks on the flywheel are as follows, 
this showing also what they indicate. In referring to these it will be 
remembered that on a four-cylinder crankshaft the first and fourth 
erankpins are up (or down) together, while the second and third are 
down (or up) together: 

1- 4 UP Means that pistons in cylinders 1 and 4 are in 

their uppermost position, or at upper dead center. 

2- 3 L T P Means that pistons in cylinders 2 and 3 are in 

their uppermost position, or at upper dead center. 

1-4 1-0 Means that inlet valve of cylinder 1 or 4 (not both) 
opens. 

1-4 I-C Means inlet valve of cylinder 1 or 4 closes. 

1-4 E-0 Means exhaust valve of cylinder 1 or 4 opens. 

1- 4 E-C Means exhaust valve of cylinder 1 or 4 closes. 

2- 3 1-0 • Means inlet of cylinder 2 or 3 opens. 

2-3 I-C Means inlet of cylinder 2 or 3 closes. 

2-3 E-0 Means exhaust of cylinder 2 or 3 opens. 

2-3 E-C Means exhaust of cylinder 2 or 3 closes. 

The firing order of the cylinders is 1- 3- 4- 2. To apply this 
knowledge, open the pet cocks so the motor will turn over easily; 
selecting cylinder 1 to start with, turn the flywheel until the mark 
1-4 UP comes to the pointer at the top. Now continue turning 
to the left (at the rear end) about an inch more when the mark 1-4 1-0 
will be seen. Bring this slowly up to the pointer, when the inlet 
valve should just begin to open. This can be noted by feeling the 
stem, or by placing a wire upon the top of the valve and noting when 
it begins to be pushed upward by the valve movement. If this should 


248 


GASOLINE AUTOMOBILES 


happen in cylinder 4 instead of 1, turn the flywheel one complete 
revolution, bringing the same point to the top. If this is entirely 
correct, the flywheel can be turned in the same direction about 5 to 6 
inches more than half a turn, when the mark 1-4 I-C will appear. 
Turn slowly until it reaches the pointer, when the valve in cylinder 1 
should be completely closed. This can be determined again by 
feeling of the valve stem which should come down to its lowest 
position, or by the wire on the top of the valve. At this point the 
valve-tappet clearance comes in. When the valve tappet has reached 
its lowest point, and the valve has been allowed to seat, the tappet 
should go down slightly farther than the valve, leaving a very small 
space between the two. This is the clearance and it varies in normal 
engines from .002 inch to .012 inch. In the motor which is being 
described it is .012 inch. The closest approximation to this is an 
ordinary visiting card, which is about .012 inch thick; when a motor 
is handled which has less, very much less, this can be approximated 
by means of cigarette papers which are very close to .003 inch thick. 
These are used in the absence of precise metal thickness gages, 
or feelers, as they are called. 

Valve-Stem Clearance. This clearance is necessary to compensate 
for the expansion of the valve stem* when it becomes highly heated 
during the operation of the engine; the tappet or push rod does not 
become heated, consequently it does not expand. Practically all 
motors are made with an adjustment here in the form of a screw with 
a hexagon head which is hardened where it strikes the valve stem or 
it is recessed out for a piece of hard fiber to deaden the noise, Fig. 151, 
and the fiber is locked in the desired position by means of a lock 
nut. If the clearance is less than the required amount or greater 
so that the motor is very noisy, the lock nut is loosened, and the screw 
gradually turned upward until it just begins to grip the visiting card. 
This should be done very carefully, for if the clearance is made too 
small, the valve will not seat fully when the motor is hot and the valve 
has expanded; on the other hand, if the clearance is made too large, 
the push rod will come up against the valve end each time with a bang, 
and eight of these repeated a thousand times a minute make a great 
deal of disagreeable and useless noise. In the modern motor, the 
cams are made an integral part of the camshaft. If the driving gear 
for the camshaft is in its right place, and the camshaft bearings are 


GASOLINE AUTOMOBILES 


249 


all in good shape, this push rod adjustment is the only valve adjust¬ 
ment possible. If the timing is not correct, that is, if none of the valve 
operations correspond with the marks on the flywheel and the maker’s 
instructions, then the cam gear has been misplaced. 

Exhaust-Valve Setting. The same procedure is followed through 
for the exhaust valve of the same cylinder, continuing past the 1-4 UP 
mark to the mark 1-4 E-O. At this point the exhaust valve of 
cylinder 1 should just begin to open. Then continue around to the 



1-4 E-C point where the exhaust valve of cylinder 1 is just complet¬ 
ing its downward, or closing, movement. If there should be any need 
for adjustment here, as described previously, this should be made 
before proceeding to the other cylinders. It should be stated that 
many makers give the exhaust-valve stems slightly greater clearance 
than the inlets, on the assumption that they work with hottei gases, 
are subjected to more heat, and should therefore expand more. The 
make being described has the same clearance for both. 

Relation of Settings in Each Cylinder. Now, having checked up 
and adjusted both valves for cylinder 1, follow through the same 






















250 


GASOLINE AUTOMOBILES 


process for cylinder 4, and, after that, of cylinder 2, then 3. The dia¬ 
gram, Fig. 162, shows but the cycle in each cylinder, while the descrip¬ 
tion above simply listed the markings to be found on the flywheel, 
so the additional diagram, Fig. 163, is given to show the relation of 
these marks to one another. This diagram refers to a different motor, 
a Hudson four-cylinder model, and the timing is indicated on the face, 
but the repair man will understand that this is done simply for con¬ 
venience, and that these marks are actually found on the rim. So, 
too, the lines drawn down to the center are simply shown for conven¬ 
ience in indicating the angles and do not appear on the flywheel. 



Fig. 164. Section through Cadillac Eight, Showing Camshaft and Valve Mechanism 
Courtesy of Cadillac Motor Car Company, Detroit, Michigan 


In this a different timing will be noted, in that the inlet opens later and 
closes earlier, while the exhaust opens earlier and closes earlier. 

System Applies to All Types of Motors. As has been stated pre¬ 
viously, discussed, and shown in Tables I and II, there is, and 
always has been, a wide divergence among designers on the subject 
of valve timing, so that the repair man must look for a different 
setting with each different make, and often a different setting with 
each different model of the same make. All that can be used for all 
cars is the general method. The general method, however, is appli¬ 
cable whether the valves are all on one side (L-head cylinders), half 




GASOLINE AUTOMOBILES 


251 


on each side (T-head cylinders), all in the head or half on one side and 
the other half in the head, in short, regardless of the valve position. 
Similarly with regard to numbers, the method holds good regardless 
of the number of valves per cylinder. Moreover, it applies regardless • 
of the number and arrangement of the cylinders, as it is just as good 
for eights and twelves as for the four described. On V-type motors 
there is a close relation ‘between the opposing cylinders, right- 
hand No. 1 and left-hand No. 1, and this must be taken into 
account. In some motors there is a cam for each valve, in which case 
no trouble would ensue; but in others there are but eight cams for 
the sixteen valves (of an eight-cylinder motor). This type of shaft 
will influence the timing diagram, and in setting, the repair man will 
have to concern himself with the same cam for two different valves- 



Fig. 165. Cadillac Camshaft, Cam Followers, and Covers Removed from Motor 


one in a cylinder of the right-hand group and one in a cylinder of 
the left-hand group. 

This statement will be more plain perhaps if reference is made to 
Fig. 164, which shows a section through the Cadillac eight for 1917, 
and indicates how the one cam operates two valves through the hinged 
rocker arms A on the left-hand cylinder and B on the right for the 
right-hand cylinder. By comparison, see also Fig. 165, which shows 
the plate C in Fig. 164 removed and turned upside down, with the 
camshaft and rockers complete. Not all eights and twelves are like 
this, nor do all have a single camshaft set in the middle of the V; 
on the contrary, one well-known twelve-cylinder motor, the Na¬ 
tional, has the valves on the outside of the two groups of cylinders, 
and thus has two camshafts. In such a case, the timing method just 
described would be followed through for all the cylinders on one block, 
then the same system would be followed through on the other side 
of the engine, one cylinder after another, on that block. 








252 


GASOLINE AUTOMOBILES 


Repairing Poppet Valves and Valve Parts 

The interest of the repair man in all these valve-motion parts is 
quite different from that of the designer, for he cares not so much 
how they are made as how they are taken out, repaired, and put back, 
when accident or wear make this work necessary. To the repair man 
suitable tools for doing this kind of work are also of interest, particu¬ 
larly those for reaching inaccessible parts or for doing things which 
without the tools could not be done. 

Curing a Noisy Tappet. Valve springs and the valves them¬ 
selves, either at the seat end or at the tappet end, give the most 
trouble. For example, when the clearance between the end of the 
tappet and the end of the valve (usually from .003 to .008 inch) is 
too great, a metallic click results. Often this noise from the tappet 

is mistaken for a motor 
knock; but the skilled 
repair man has little 
trouble in finding and 
remedying it, for, even 
if he cannot measure in 
thousandths of an inch, 
he knows, for instance, 
that the ordinary cigar¬ 
ette paper is about .003 
inch in thickness, and 
from this he can estimate 
.003, .006, or .009 inch. Ordinary thin wrapping paper is well 
known to be about .005 inch; with this alone, or in combination 
with cigarette papers, he can obtain .005, .008, .010, and .011 inch, 
practically all the variation he is likely to need. 

Removing Valve. Getting the valve out frequently gives much 
trouble; the valve is often found frozen to its seat or to the stem 
gummed in its guide. A tool to meet this difficulty is a plain bar 
or round iron about | inch in diameter, Fig. 166, with one end, for a 
distance of perhaps 2 or 2\ inches, bent up at an angle of about 120 
degrees. To use the tool, insert the short bent end in the exhaust 
or the inlet opening, according to which valve is stuck, until the end 
touches the under side of the valve head, then lower the outer end 
until the bottom of the bent part or point at which the bend occurs 



Fig. 166. Bent Tool Which Facilitates Removal 
of Stuck Valves 



































GASOLINE AUTOMOBILES 


253 



Fig. 167. 


Easily Made Tool for Removing 
Valve Spring 


rests against solid metal. The outer end can now be pressed down, 
and, w ith the inner end acting as a lever, the valve can be pressed off 
its seat and out very quickly. 

To make this clearer, the rod, Fig. 166, is indicated at A, while 
the dotted line shows how it is pressed down and the valve forced out. 
The garage man can elaborate upon the tool when making it for 
himself by using square stock; 
it has the inner end forked so 
as to bear on each side of the 
valve. The form pointed out 
above is the simplest, cheap¬ 
est, and easiest to make. 

Removing Valve Spring. 

Taking out the valve spring 
is frequently difficult for 
various reasons; perhaps the 
springs are very stiff, or they 
may have rusted to the valve cups at the bottom, or the design 
may not allow room enough to work, etc. At any rate the 
removal is difficult, and a tool which will help in this and which 
is simple and cheap, is in demand. Many motor cylinders are cast 
with a slight projection, or shelf, opposite the valve-spring positions, 
so that one only needs a tool that will encircle the lower end of the 
valve spring and rest upon this ledge and give an outer leverage. 

Types of Valve Removers. 

In working on cylinders that 
do not have this cast pro¬ 
jection, a tool like that shown 
in Fig. 167 is useful. It con¬ 
sists of a yoke for encircling 
the lower end of valve spring 
and cup, with a long outer 
arm for prying, and a slot into which a drilled bar is set. This 
bar is placed in various positions according to the kind of motor 
which is being worked on; when removing a valve-spring key, the 
lower end of the bar rests upon the crankcase upper surface, or 
upon the push-rod upper surface if that is extended. After slipping 
the grooved yoke under the spring cup, a simple pressure on the outer 



Fig. 168. 


Type of Valve-Spring Tool Which 
Leaves the Hands Free 


















254 


GASOLINE AUTOMOBILES 




end raises the valve so the key can be withdrawn. Then the removal 
of the tool allows the valve spring to drop down, and the valve is free 

The valve spring may be 
removed in two other ways by 
the use of the two tools shown in 
Figs. 168 and 169. In the former, 
the idea is to compress the spring 
only, no other part being touched. 
This tool, once set, will continue 
to hold the spring compressed, 
leaving the hands free—a decided 
advantage over the tool shown in 
Fig. 167. This device consists, as 
the illustration shows, of a pair 
of arms with forked inner ends 
and with outer ends joined by a 
pin. bent-lmndled screw draws 
the ends together or separates 
them, according to which way it 
is turned. 

The simplest tool of all is the 
one shown in Fig. 169. It is a 
formed piece of stiff sheet 
metal which is set into 
place when the valve is 
open, and when the valve 
is closed by turning the 
motor, the sheet-metal 
piece holds the spring up 
in its compressed position. 

There are almost as 
many different valve and 
valve-spring removers as 
there are different cars or 
different m o t o r s. How¬ 
ever, the simple makeshift 
Lacking a form of valve- 

i 


Fig. 1G9. Substitute for a Valve Spring 
Remover Which Pushes Spring away 
as Motor is Turned 


Method of Compressing Valve Spring without 
Special Tool 

Courtesy of "Motor World" 


shown in Fig. 170 is worthy of mention, 
or spring-removing tool, this repair man simply supported a plaii 











































GASOLINE AUTOMOBILES 


255 


double-ended wrench by means of a wire attached to the water 
pipe on top of the motor; adjusting the length of it so that the 
end of the wrench would just slip under the valve key, he was 
able to remove the pin, which freed the spring and thus the 
valve. Practically the same thing was evolved by another repair 
man who took a wrench of this type and drilled a hole through the 
center of the handle which was first twisted through a right angle. 
Then he bent a piece of stout wire into the form of a hook, one end 
through the wrench, the other over some projection on the engine. 
With the hook removed, the wrench was not radically different from 
any other and could be used as freely; with the hook in, he had a 
simple valve-spring removing tool. 



Fig. 171. Method of Compressing All Twenty-Four Packard Valve Springs at Once 

Courtesy of “Motor World ” 


Twelve-Cylinder Valve Remover. One of the objections raised to 
the twelve-cylinder motor is the trouble of removing and grinding all 
the valves. The Philadelphia Branch of the Packard Company has 
overcome this disadvantage by constructing the special tool shown in 
Fig. 171. This lifts the whole 24 valves at once. It consists of the 
central stand, which rests on the flat top of the crankcase, having a 
long arm and connected levers at the bottom to work the spring com¬ 
pressors. These, as will be seen at A and It, are really the special 
feature of the outfit, as they are specially constructed to fit around the 
valves in sets of 12 each. A ratchet holds the device locked, so that 
after it is applied and fitted to all the valves, they can be forced up 
and locked; then the matter of valve removal, regrinding, and replace- 
















256 


GASOLINE AUTOMOBILES 


ment can be handled for the whole 24. At its conclusion, the rigging 
can be unlocked and all 24 valves freed at once. 

Holding Valve Springs Compressed. Many times there is a 
need for holding the spring in its compressed form, as, for instance, 
when the valve is removed with the positive certainty that it will be 
replaced within four or five minutes. In such a case a clamp which 
will hold it in compression is very useful, for it saves both time and 
work. These may be made to the form shown in Fig. 172 in a few 
minutes’ time, for they consist simply of a pair of sheet-metal strips 
with the ends bent over to form a very wide U-shape. A pair of 
these is made for each separate make of valve spring, because of the 

varying lengths, but they are so 
easily and quickly made that 
this is no disadvantage. 

In many shops, after getting 
in the habit of making these 
clamps, the workmen take this 
way of replacing the spring in 
preference to all others. After 
removal of the valve, the spring 
may be compressed in a vise and 
a pair of the clamps put on. 
Then when the valve is ready to 
go back in, the spring is as easy 
to handle as any other part. This is especially true when replacing 
the spring retainer and its lock. 

Stretching and Tempering Valve Springs. Many times when 
valve springs become weakened, they can be stretched to their former 
length, so that their original strength is restored. This can be done 
by removing them and stretching -each individual coil, taking care 
to do it as evenly as possible. When well stretched, it is advisable 
to leave the coils that way for several days. This method will not, 
of course, restore the strength permanently; it is at best a makeshift, 
for in the course of a few thousand miles the springs will be as bad 
as before. 

Sometimes weakened valve springs may be renewed by retem¬ 
pering, on the theory that the original temper was not good or they 
would not have broken down in use. The tempering is done by 























GASOLINE AUTOMOBILES 


257 


30—| | 

—36 

40— IJ 




to —(] 

—— 

■—U 



heating to a blood-red color and quenching in whale oil. If this 
is not successful, new springs are advised. 

Adjusting Tension of Valves. Unless all the valves on a motor 
agree, it will run irregularly, that is, all the exhausts must be of 
the same tension, and all the inlets must agree among themselves, 
though not necessarily with the exhausts. Many times irregular 
running of this kind, called galloping, is more difficult to trace 
and remove than missing or some other form of more serious trouble, 
and it is fully as annoying to the owner as missing would be. 

To be certain of finding this 
trouble, the repair man should 
have a means of testing the 
strength of springs; a simple device 
for this purpose is shown in Fig. 

173. As will be seen, this consists 
of sheet-metal strips and connect¬ 
ing rods of light stock, with a hook 
at the top for a spring balance and 
a connection at the bottom to a 
pivoted hand lever for compress¬ 
ing the spring. By means of the 
center rod at R and the thumb 
screw at the bottom, the exact 
pressure required to compress the 
spring to a certain size may be 
determined. Suppose the spring 
should compress from 4 inches to 
3 J inches under 50 pounds. By compressing it in the center portion 
of the device, so that the distance between the two adjacent strips of 
metal indicated by S is just 3J inches, the spring balance should show 
just 50 pounds. If it shows any less, the spring is too weak arid 
should be discarded; if it shows any more, it is stronger than normal 
—which is desirable if all the other springs on the same engine are 
also stronger. 

If only, a quick comparison of four springs is desired, the device 
can be made without the bottom lever, as the setting of S at a definite 
figure—say to a template of exact length—would call for a certain 
reading of the scale of the spring balance. 



Fig. 173. Simple Rigging for Testing Valve- 
Spring Pressure and Strength 































258 


GASOLINE AUTOMOBILES 


Set Screw 
Valve Stern^ 



Set Screw 


Cutting Valve=Key Slots. Cutting valve-key slots in valve 
stems is another mean job which the repair man frequently meets. 
He runs across this in repairing old cars for which he has to make 
new valves; and at other times for other repairs. The best plan is to 
make a simple jig which will hold, guide, and measure all these things 
at once, as all are important. Such a jig is shown in Fig. 174. It con¬ 
sists of a piece of round or other bar stock, in which a central longi¬ 
tudinal hole is drilled to fit the valve stem, one end being threaded for 
a set screw. Near the other end of the jig, three holes, of such a 
diameter as to correspond with the width of key slot desired, are 
drilled in from the side. These are so placed that the length from 
the top of the upper hole to the bottom of the lower gives the length 
of key seat desired. Opposite the three drilled holes and at right 
angles to them, another hole is drilled and tapped for a set screw. 

To use the device, slip the 
valve in place and set the bottom 
screw of the jig so as to bring the 
three drilled holes at the correct 
height for the location of the key 
seat. Then the three holes are 
drilled, and the valve is moved upward so that the space between 
the holes is opposite a guide hole, and two more holes are drilled to 
take out the metal between. The five holes will give a fairly clean 
slot, which needs a little cleaning out with a file before using. 

Grinding the Valves. The new driver must learn when to grind 
his valves, that is, how often, and he must also learn to do the 
work properly. There is no hard and fast rule which can be given 
aside from grinding when it is necessary. A careful driver may get 
four to five thousand miles out of his valves with one grinding, while 
another may get only one or two thousand miles with the selfsame 
car and engine. There are many factors which enter into the life 
of a valve seat, and, in the frequency of grinding, all of these have 
to be taken into account. Some of these are: imperfect cooling of 
the seats; too strong springs, which cause hammering and thus wear 
out the seats prematurely; over-lubricating, which causes spitting 
and sooting, both of which reduce the active life of the valve seat. 

Another cause for frequent grinding is contributory negligence 
on the part of the driver. He does not examine them as often as he 


Valve Head'll 
Fig. 174. Cheap Jig for Slotting Valve Stems 























GASOLINE AUTOMOBILES 


259 


should, and the result is failure to discover something in the way of 
soot or dust caught in between the valve and seat, which is being 
gradually pressed into the seat. 

Reg rinding Process. When either the valve head or seat has 
become worn or pitted, it must be reground as follows: Secure a small 
amount of flour of emery, the finer the better, and mix this into a thin 
paste using cylinder oil, or graphite, or both. Loosen the valve, dis¬ 
connect all attachments, remove the valve cap above, and free the valve 
in a vertical direction. Now lift it out, place a daub of the emery 
paste on the seat, and replace the valve. With a large screwdriver 



Fig. 175. Two methods of Grinding-In Valves: (A) by Hand, Using a Screwdriver; 

( B) with Brace, Screwdriver and Bit 


press the valve firmly in place, at the same time rotating it. about 
one-fourth of a turn to the right and then the same amount to the left. 

This is shown in Fig. 175-A, in which S is the screwdriver, V 
the valve, and VS the valve seat. Note how the right hand presses 
down on the screwdriver and turns it at the same time. While this 
is being done, the left hand should be held right below the valve 
stem with one finger just touching it. After moving back and forth 
about eight or ten times, lift the valve off its seat with the finger, 
turn it through a quarter-turn, and drop it back into place. Then 
repeat the grinding until the whole circle has been covered several 
times. Then remove the valve and clean off both moving member 
and seat with gasoline. Mark the seat on the valve with a slight 

































260 


GASOLINE AUTOMOBILES 


touch of Prussian blue, replace the valve, and twirl it around several 
times so as to distribute the color. Remove the valve without touch¬ 
ing the seat portion on it or in the cylinder, and examine both. If 

the grinding process has been complete and accurate, the color will 

* 

have been distributed in a continuous band of equal width all around 
the surface. If not continuous, or not of equal width all around, the 
task is but partially completed and must be continued until the full 
streak results. On the first attempt at this rather delicate piece of 

work, it is well to call in an expert repair 
man to examine and pass upon the job. 

In Fig. 175-R the same process is 
shown, but a brace, screwdriver and bit are 
used in place of the slower screwdriver. 
This method would hardly be advocated 
for an amateur attempting his first job of 
valve grinding, but as soon as some pro¬ 
ficiency has been attained, it is the best, 
quickest, and most thorough method. 

There are, of course, a number of tools 
now on the market for grinding valves; 
some of these are constructed in such a 
manner as to do all the work, namely, the 
partial turn and reverse on the grinding 
stroke, then the lift and partial revolution, 
then dropping the valve down on the seat 
again, and repeat. The use of one of 
these reduces the act of valve grinding 
down to a matter of knowing how to apply 
the emery and when and how to stop. 

Noisy Valves. Sometimes the valves get very noisy and 
bother the driver a great deal in this way, that is to say, the wear 
in the valve-operating system becomes so considerable as to make 
a noise every time a valve is opened or closed. With the engine 
running at slow speeds, each one of these is heard as a separate small 
noise and not much is thought of it, but when the motor is speeded 
up, the noises all increase and become continuous and very notice¬ 
able. This may be remedied by taking up on the valve tappets 
which usually are made adjustable for this purpose. They should 



Fig. 176. Method of Enclosing 
Valve Action with Pasteboard 
Tube to Stop Noise and Im¬ 
prove Lubrication 














GASOLINE AUTOMOBILES 


261 


be taken up until there is but a few thousandths of an inch between 
the v alve tappet and the lower end of the valve stem. A good way to 
measure this is to adjust until one thickness of tissue paper will just pass 
between the two; then there is approximately .003 inch between them. 

Valve Enclosures. On many old cars, the arrangement of the 
\al\e mechanism is such that, after several thousand miles have 
been covered, the valve motions will become noisy and nothing that 
can be done will stop this. In that case, the best plan is to enclose 
each one of them in a pasteboard or other tube and thus keep the 
noise in. In fact, this is 
a good plan even for later 
models. The method of 
doing this is indicated in 
Fig. 176, in which the 
pasteboard tube is shown 
in place around the valve 
mechanism. Asthis 
should be a tight fit be¬ 
tween the crankcase at 
the bottom and the cyl¬ 
inder at the top, the tube 
must be slit in order to 
get it on. When this 
has been done, however, 

the tube can be drawn together and fastened by means of wire or 
otherwise. Besides reducing the noise, it will be found that the 
valve system parts will get better lubrication in this way and will pick 
up less dirt and dust, thus wearing less. 

Taking Out a Valve. On some engines the job of taking out a 
valve or valves is not as simple as it sounds. On an overhead engine, 
or an engine with overhead valves, it is not as hard work as on an 
engine with the valves in pockets in the side of the cylinder, for the 
overhead valves are usually set into removable seats. The latter 
come out by simply taking off a yoke or, at most, a pair of nuts, and 
then the cage and with it the valve lifts right out, spring and all. 
This latter is mentioned because with the ordinary L- or T-head motor, 
it is the spring which causes all the trouble. Fig. 177 shows the 
process of removing the cage and valve from an engine with overhead 



Fig. 177. Removing Valves from a Truscott 
Marine Engine 




262 


GASOLINE AUTOMOBILES 


valves (this is the engine made for the Truscott boats). To remove 
these, the valve tappet is held out of the way and the cage unscrewed. 

Troubles with Inlet Valve. The inlet valve is often the seat of the 
trouble, and missing here is generally caused by a weak or broken 
spring, a bent stem, or a carbonized valve. If the valve spring has 
lost its temper and broken down, the tension will be insufficient to 
properly hold the valve on its seat, and the gas will partially escape 
and so cause missing. The insertion of an iron washer or two will 
increase the tension of the defective spring and serve as a temporary 
road repair. A broken spring may be similarly repaired by placing a 

washer between the broken ends. 
A bent valve stem should be 
taken out and carefully straight¬ 
ened by laying it upon a billet of 
wood with another block inter¬ 
posed between it and the ham¬ 
mer. Only a very little force is 
needed, and the stem should be 
repeatedly tried until it slides 
freely in its guide. 

Valve Timing Gears. As has 
been stated, the camshaft is gen¬ 
erally gear-driven from a crankshaft by a pair of two-to-one reduc¬ 
tion gears; these are simple spur gears with straight or spiral teeth. 
As the one gear is keyed to the crankshaft and the other to the cam¬ 
shaft, it is highly important that these two gears be meshed in an 
exact manner. If one of them is out as little as one tooth, the differ¬ 
ence in the running of the engine will be very marked. The timing 
previously mentioned under the head of Valve Timing will not be 
obtained; either all operations will occur later than the valve timing 
diagram and instructions call for, or else all these will be earlier. In 
either case, there will be a loss of speed and power, accompanied 
by noise, and the engine will not throttle down or speed. 

To avoid this difficulty for the repair man, all gears are set and 
marked correctly at the factory. The marking is done in several 
ways. One is by lines cut on the gears when correctly meshed, so 
that if the gears are correctly meshed later, the part of a line on one 
gear will be a prolongation of the part on the other. Another way is 



Fig. 178. Marking Timing Gears Is a Simple 
Job and Saves Much Time and Trouble 





GASOLINE AUTOMOBILES 


263 


to use center punch marks, one mark between the teeth on one and 
on the tooth meshing with these on the other. Then, if a second 
place has to be marked, two prick-punch marks are used in a similar 
manner, and if a third is marked, three punch marks. A third method 
is the use of numbers, the first pair marked being numbered 1 on each 
gear at the point of meshing, the second pair marked 2 on each, etc. 

For the second method, all that is necessary is a prick punch and 
hammer, used in the manner shown in Fig. 178. When there are but 



two gears, as in the case shown, it is easy to make one hole between 
two teeth on one gear and another which lines up with it and as close 
to it as possible on the other gear. Where there are three, four, or 
more gears, the usual practice is to make the first and third with two 
prick-punch marks on each, the others with three, four, etc. 

For the third method, or the use of numbers, see the set of gears 
shown in Fig 179. This figure is that of the engine whose timing 
was described and shown in Fig. 162. It has four gears; from right 





































I 


264 GASOLINE AUTOMOBILES 

to left they are camshaft gear, crankshaft gear, idler gear, and magneto 
gear. As will be noted, the crankshaft gear meshes with two others, 
so it must be marked in two places, 1 where it meshes with the cam¬ 
shaft gear and 2 where it meshes with the idler. A moment’s thought 
will show, however, that it could never be replaced in the wrong 
manner, since it is marked only on the outside face, its 1 and ^figures 
show where it matches a 1 mark on one gear and a 2 mark on another. 

Chain Drive for Camshafts. The silent chain has gained much 
popularity for camshaft and accessory drives in the last two years for 
a number of reasons. It saves the use of idler gears in such cases as 



Fig. 180. Silent-Chain Drive for Packard Twelve, Showing Method of Marking 

that just illustrated and described; it allows the placing of the cam¬ 
shaft and other shafts anywhere desired (at least in so far as the gear 
is concerned); it is more quiet than the gear drive in the prescribed 
position which the two-to-one reduction necessitates; it is less 
expensive to construct and apply, and it weighs slightly less. The 
teeth on the silent-chain gearing are called sprocket teeth, while those 
on the two-to-one reduction are called gear teeth. 

In the silent-chain drive for camshaft and accessories, which is 
shown in Fig. 180, it will be noted that there is a line scribed vertically 
across both gears and the crankcase, with prick-punch marks on the 
case at A, on the camshaft sprocket at BB, and on the crankshaft 




























GASOLINE AUTOMOBILES 


265 


Roller 

Spring Cup 
Pin 


Cylinder Send 


sprocket at CC. This makes its correct adjustment easy. A 
straightedge is laid across the case marks, the crankshaft sprocket 
tumed to this line, and the chain put in place but not joined; finally 
the camshaft sprocket is turned to the line, the chain moved to hold 
it in this position, and its ends joined. By this method, there would 
be two possible positions for the camshaft sprocket, as compared with 
the crankshaft sprocket and line on the case. These could readily 
be distinguished as correct and in¬ 
correct as soon as the chain is applied 
and the engine given a couple of 
turns. If incorrect, it is simply a 
matter of lining them up again by 
opening the chain, turning the cam¬ 
shaft gear through 180 degrees, 
putting the chain back on and join¬ 
ing its ends a second time. 

Other Parts of Valve System. 

There are a number of other parts in 
the valve group whose names and 
functions should be explained, for 
these are of interest to both the 
owner and the repair man. The 
repair man should know what work 
they do in order to be able to repair 
them successfully. Fig. 181 shows 
an overhead-valve system in which 
the camshaft is in the usual place 
in the crankcase; long push rods are 
used with rocker arms, or levers, at 
the top. This is mentioned because 
many, in fact the majority of, motors with overhead valves have 
an overhead camshaft like the Chalmers, Fig. 156. 

In this figure the various parts are named. The rotation of the 
camshaft brings the cam around so that it lifts the roller and plunger 
which has the adjusting screw and its lock nut at the top. The top 
of the roller bears against the bottom of the push rod, and the 
upper end of the push rod operates the valve rocker lever which is held 
in the support. At the other end of the valve rocker lever a roller 



- Va/ve L if/(r(orPuih Rod) Guide . 
Crank Case 


-Rotter 
Cam Shaft 
■Cam 


Fig. 181. Typical Overhead-Valve Layout, 
Showing Complete Mechanism 























































266 


GASOLINE AUTOMOBILES 


presses against the top end of the valve stem and pushes it down from 
off the valve seat against the pressure of the spring, the upper end 
of which is held by the cup and cup pin and the lower end rests 
upon the upper surface of the valve cage. The latter is made so 
that its central upward extension also forms the valve guide. The 
valve cage is screwed down into the cylinder head with packing to 
make a gas-tight joint. It carries the valve seat and is cored out for 
the gas passages through which the gas enters (or leaves). 

When the valve in pockets is substituted for the long push rod, in 
either the L-head or in the T-head cylinder, the construction is about 
the same as if the upper right-hand valve group were lifted bodily, 
turned upside down, and placed so that the upper end of the valve 
stem, upon which the roller rests, comes into contact with the adjust¬ 
ing screw. In that case, the 
valve lifter would be called the 
push rod, and the valve cage 
would become a part of the cylin¬ 
der with an integral or, in some 
cases, a removable valve guide. 

Push Rods and Guides. As 
can be seen from Fig. 181 and 
the explanation accompanying 
it, the push rod and its guide, or 
lifter and guide, become impor¬ 
tant. The shape of the cam is 
such that it deals the roller and 
lower end of the push rod, or lifter which holds it, a fairly heavy 
blow sideways each time it comes against it. If the roller and 
rod are not a perfect fit, something will yield each time, and the 
roller will wear oval in a short time. The movement and noise 
will increase rapidly and soon become very objectionable. The only 
remedy is replacement. These guides are held in place in one of two 
ways; either individually by means of a pair of bolts or in pairs by 
means of a yoke and a single central bolt and nut of large diameter. 
The Locomobile, Fig. 151, shows the former method; the Haynes, 
Fig. 152, the latter method. These, however, are end views which do 
not bring out the point as clearly as Fig. 182. Here the arrow points 
to the nut midway between the two push rods, which holds down 



Fig. 182. Method of Holding Two Push Rods 
with Yoke and Single Central Nut 





























GASOLINE AUTOMOBILES 


267 


the yoke that rests upon shoulders on the push rods and holds them in 
place. From a repair man’s point of view, the latter construction is 
better, for the push rods can be removed and replaced much more 
easily and quickly. 

Valve Cage Repairs. When the valves are in overhead cages, it 
is highly important that they fit tightly in the cylinder head; they 
must be ground in as carefully and as tightly as the valves are ground 
into their seats. Where a shop handles a good many motors of the 
overhead-valve type, it is desirable to make a rig to do the grinding 
easily. One of these rigs is shown in Fig. 183. It consists of a shaft 
and handle with lock nuts for 
the valve cages used on Buick 
On these cars, it is in two 


cars. 



Yalve 

Caqe 


parts; the cage proper, and the 
locking member which screws into 
the cylinder. Obviously the cage 
is the one to be ground in. The 
rig shown slides in the central 
opening, that is, fits in the valve 
guide, and has a lock nut top 
and bottom to fasten it tightly. 

When fitted into place firmly, the 
right-angle bend in the rig gives 
a handle by means of which the 
cage can be lifted in and out and, 
what is more important, rotated 
on its seat. When the cage is 
prepared, the seat is given a little oil and emery or oil and powdered 
glass or prepared valve grinding composition, the cage is set in place 
and ground in the same as a valve, that is, with one-third to one-half 
rotations in one position, then lift, move around, and repeat in the 
new position, continuing this until the whole surface of the cage in the 
cylinder has been covered twice. I his should result in a good seat. 

When the valves in an overhead motor need grinding, the valve 
and cage are taken out completely and held in an inverted position 
in a vise or other clamp, and the valve ground in to the seat in the 
cage in the regular way. It is said this can be done very lapidly and 
well by chucking the valve stem, as it projects from the cage, in a 


Fig. 183. Simple Fixture for Grinding-In 
Overhead Valve Cages 

Courtesy of “ Motor World” 




































































































268 


GASOLINE AUTOMOBILES 


Where the leather u/as fitted 



Fig. 184. Method of Curing Valve- 
Guide Leak Quickly and Cheaply 


lathe rotating at a very slow speed, and operating the cage by hand, 
that is, slide the cage back, apply grinding compound, then move the 

cage up to the rotating valve and hold 
it with the hand while the valve is 
turning with the lathe. In holding it 
thus, the pressure endwise should be 
very light. 

Valve Guides. The valve stem 
must be a tight fit in the guide, other¬ 
wise air will leak through into the 
combustion chamber and dilute the 
mixture, or the compression will leak 
out, or both. Any valve leak will affect 
the running of the motor, so it should 
be stopped at once. Two methods of 
temporarily remedying small leaks are 
shown in Figs. 184 and 185. A simple leather washer with a small hole 
through the center, which fits tightly over the valve stem, is pressed 
up around the outside of the guides, as shown in Fig. 184. This 
simple repair was very effective, and the leather washers lasted an 

astonishingly long time. The other 


same result arrived at differently. In 
this case, old spark-plug shells, with con¬ 
siderable recesses in the center part, were 
turned down so as to fit around the bot¬ 
tom of the guides. These recesses were 
packed with felt or other available pack¬ 
ing, care being taken to pack the recesses 
tightly. Then the whole thing was held 
up in place by a lighter spring put inside 
the main valve spring. By adding a few 
drops of oil to the packing now and then 
to keep it soft, it lasts almost indefinitely. 

The valve-guide hole in the cylinder 
is generally made as long as possible, 



Fig. 185. Remedy for Leaky Valve- 
Stem Guide, Using Old Spark 
Plug and Felt 


both to give a straight and true hold on the valve stem and thus 
maintain its straightness in spite of the heat, and to give a long 



















































GASOLINE AUTOMOBILES 


269 


\ 

wearing surface. This length and the need for accuracy through¬ 
out makes the valve-guide hole an awkward surface to repair. 
When worn beyond any hope of simple repair, it is best to ream it out 
and press in a bronze bushing so that the valves can still be used. 
An excellent tool for this purpose, developed for Dodge motors but 
which is usable for almost any motor, is shown in Fig. 186. This con¬ 
sists of a high threaded bushing which is clamped to two diagonal 
cylinder studs. The thread inside the bushing is very fine. A long 
tube, with the lower end bored out to take a standard reamer, is 
screwed into it. The top is squared and a handle is made to fit it. 
When the handle is turned, the 
tube is gradually screwed down 
into the cylinder, carrying the 
reamer slowly but truly down 
through the valve guide. This 
rigging is simple, easily made, and 
gives accurate results. When 
the valve-guide hole is reamed, 
the bushing can be turned up 
and pressed in with any form of 
shop press. 

Valve Caps. The plug which 
fits into the top opening in the 
cylinder through which the valve 
is put in place and removed is 
called the valve cap. Sometimes 
it has external hexagonal sides 
so it can be easily removed, but 
more often it has an internal hexagon, or internal i ibs. The 
latter form can be removed most easily by constructing a special 
tool, consisting of a cylindrical member, with a bottom diameter 
slightly larger than the opening in the valve cap, with four (or 
more) teeth, or projections, set into the bottom of this to match the 
ribs inside the cap. A central hole is drilled for a bolt with spaik- 
plug threads at the bottom. To use the member, remove the spark 
plug, set the device in place, slip the central bolt in and screw it down 
into the plug to hold the whole thing in place,* then apply a 
wrench to its upper square surface and remove the valve, cap and all. 



Fig. 186. Rigging for Reaming Out Valve- 
Stem Guide Holes 

Courtesy of “ Motor World" 


































































270 


GASOLINE AUTOMOBILES 



Fig. 187. Reamer for Clearing Out 
Threads of Valve Cap 

Courtesy of “Motor World” 


It can be laid aside just as removed, and when the work is concluded, 
the whole thing can be screwed back in, the central screw loosened, 

and the rig removed from the cap. 

Sometimes the threads in the 
cylinder into which the valve cap 
screws become dirty, slightly cut 
up, or marred so that the cap does 
not screw in or out readily. By 
taking an old valve cap of the same 
motor and same threads and fluting 
these in a milling machine, as indi¬ 
cated in Fig. 187, a neat tap can 
be made which will clean out the 

threads in a jiffy. It is simple, effec- 

% 

tive, and cheap. 

Cleaning Camshaft Gears. On the majority of engines, the cam¬ 
shaft and other gears or the silent chain which replaces them, are lubri¬ 
cated automatically by the running of the engine as they are by-passed 
in on the engine lubricating system. This is an excellent feature, but 
it leads to neglect. These gears or sprockets are sure to wear, and 
the metal worn off remains in the case. Moreover, dust and the 

impurities of the oil are bound 
J°\ to get in. The foreign matter 

has a cutting action on gears, 
chains, or bearings, so the 
gear case should be cleaned 
out frequently. This is done 
best by thoroughly flushing 
out the case and the gears, 
or sprockets and chains, as 
the case may be, with kero¬ 
sene. After using the kero¬ 
sene, use gasoline along with 
the kerosene to clear away any 
remaining dirt or oil. After 
applying the gasoline, wait long enough for it to evaporate before 
replacing the parts, while it might be considered extravagant to use 
both, it really is economical of time. 



Fig. 188. 


Checking up Camshaft in Milling 
Machine 






































GASOLINE AUTOMOBILES 


271 


Twisted Camshafts. With the present form of camshaft having 
the cams forged integral, troubles and irregularities between one 
cylinder and another, which the repair man finds difficult to trace or 
run down, sometimes develop in the running of the engine. A fairly 
light camshaft will sometimes become twisted, usually right 
at a cam where the stress is. When trouble of this kind is indi¬ 
cated, the camshaft should 
be removed and tested. A 
good way to do this is to 
place the shaft in the milling 
machine with the index head 
set so that one revolution of 
the shaft can be divided 
into four equal parts. Place 
a thin disc in the arbor, 
then mount the shaft and 

bring it up to the disc. 

Choose one of the cams and 
set the disc to the exact 

center of the point of it. 

Then, by turning the shaft a 
quarter-turn each time, the 
other cams can be tested with 
their relation to this one. 

Sometimes a difference of J 
inch will be found in this 

Way. The lay-out foi this IS Fig. 189. Section through Ledru (French) 

• T?* i oo Camless Engine. The Rotary Gear- 

Seen in Fig. loo. Driven Sleeve Displaces All Cams 



DETAILS OF SLIDING=SLEEVE VALVES 

A method of avoiding cams, and with them all cam troubles, is 
the use of a sliding sleeve in place of a valve, slots in the sleeve cor¬ 
responding to the usual valve openings, both as to area and timing. 
The sleeves may be operated by means of eccentrics by various lever 
motions, or by a direct drive by means of agear mounted on a separ¬ 
ate shaft. 

Gear Control. An example of the application of a worm and 
gear for this purpose to a French two-cycle engine is shown in 








































































272 


GASOLINE AUTOMOBILES 


Fig. 189, although there is nothing in its construction which would 
prevent its use on the more usual four-cycle engine. 

In this figure, P is the usual crankshaft, Q the large end of the 
connecting rod K, while A is the piston and R the crankcase, no 
one of these differing from those in other engines. On the crankshaft 
there is a large gear F, which drives a smaller gear E, located on a 
longitudinal shaft above and outside of the crankcase. On this shaft 
is located a worm gear D, which meshes with a worm C formed inte¬ 
gral with the sleeve surrounding the piston B. Aside from this worm 
gear, the sleeve is perfectly cylindrical, being open at both ends. It is 
placed outside of the piston, between that and the cylinder walls. 
At its upper end, it has a number of ports, or slots, cut through it, 
which are correctly located vertically to register, or coincide, with the 
port openings in the cylinder wall when the sleeve is rotated. One 
of these is seen at H; the exhaust, while 90 degrees around from it, 
and hence invisible in this figure, is a similar port for the inlet. As 
the crankshaft rotates, the side shaft carrying the worm is con¬ 
strained to turn also. This turns the worm which rotates the worm 
wheel on the sleeve. In this way, the openings in the sleeve are 
brought around to the proper openings in the cylinder, and the com¬ 
bustion chamber is supplied with fresh gas, the burned gases being 
carried away at the correct time in the cycle of operations. 

With a motor of this sort, the greatest question is that of lubri¬ 
cation. The manner in which it is effected in this case is by means 
of the large wide spiral grooves shown at 00 and the smaller circular 
grooves at the upper end M. Another method which renders this 
problem more easy of solution is by the machining of the sleeve; 
during this operation much metal is cut away along the sides so that 
the sleeve does not bear against the cylinder walls along its whole 
length but only for a short length at the top and a still shorter length 
at the bottom. 

Knight Sleeve Valves. In the last few years, tremendous 
progress has been made here and abroad with the Knight motor, 
named after its Chicago inventor. In many important factories 
this valve has displaced the poppet valve. In a regular four-cylinder 
four-cycle engine, the valves consist of a pair of concentric sleeves, 
the openings in the two sleeves performing the requisite functions of 
valves in the proper order. These sleeves, as Fig. 190 shows, are 


GASOLINE AUTOMOBILES 


273 


actuated from a regular camshaft—running at half the crankshaft 
speed and driven by a silent chain—by means of a series of eccentrics 
and connecting rods. In the figure, A is the inner and longer sleeve 
and carries the groove or projection C at its lower end. The collar 
actuating the sleeve is fixed around and into it. This collar is 



Fig. 190. Willys-Knight Engine in Which Eccentrics and Sliding Sleeves Replace 

Cams and Valves 


attached to the eccentric rod E, which is driven by the eccentric shaft 
shown. The collar D performs a similar function for the outer 
sleeve B. 

At the upper ends of both sleeves, slots G are cut through. 
These slots are so sized and located as to be brought into correct 

























































































































274 


GASOLINE AUTOMOBILES 


l 


TABLE III 


Royal Automobile Club’s Committee Report on Knight Engine 


Motor horsepower—R. A.C. . 

Bore and stroke. 

Minimum horsepower allowed 

Speed on bench test. 

Car weight on track. 

Car weight on road. 

Duration of bench test. 

Penalized stops. 

Non-penalized stops. 

Light load periods. 

Average horsepower. 

Final bench test. 

Penalized stops. 

Light load periods. 

Average horsepower. 

Mileage on track. 

Mileage on road. 

Total time on track. 

Average track speed. 

Fuel per brake horsepower per 

Car miles per gallon. 

Ton miles per gallon. 


hour<! 


.38.4 

22.85 

. 124 by 130 

96 by 130 

.50.8 

35.3 

. 1200 r.p.m. 

1400 r.p.m. 

.3805 lb. 

3332.5 lb. 

.4085 lb. 

3612.5 lb. 

. 134 hours 15 min. 

132 hours 58 min. 

.None 

None 

.Five—116 min. 

Two—17 min. 

. 19 min. 

41 min. 

.54.3 

38.83 

. 5 hours 15 min. 

5 hours 2 min. 

.None 

None 

. 15 min. 

1 min. 

.57.25 

38.96 

1930.5 

1914.1 

.229 

229 

. 45 hours 32 min. 

45 hours 42 min. 

.42.4 m. p. h. 

41.8 m.p.h. 

[First bench .679 pt. 

.739 pt. 

j test.613 lb. 

.668 lb. 

1 Final bench . 599 pt. 

.749 pt. 

1 test.541 lb. 

.677 lb. 

/On track. ... 20.57 

22.44 

10n road. 19.48 

19.48 

/On track .... 34.94 

33.37 v 

\On road. 35.97 

31.19 


relation to one another and to the cylinder ports and the exhaust at 
II and inlet at I, in the course of the stroke. 

It might be thought that the sliding sleeves would eat up more 
power in internal friction than would be gained, but a very severe 
and especially thorough test of an engine of this type, made by the 
Royal Automobile Club of England, an unbiased body, proved that 
for its size the power output was greater than that of many engines 
of the regulation type. Moreover, the amount of lubricating oil 
was small. 

The results of the test are shown in Table III. After the test 
was concluded, both the sleeves, Fig. 191, were found to show still 
the original marks of the lathe tool. This proved conclusively that 
the principle of this type was right, for the tests were equivalent to 
an ordinary season’s running. 

The slots which serve as valve ports are at G, Fig. 191. The 
longer sleeve A is the inner one. At the bases of the sleeves are 
the collars and pins D by which the connecting rods are attached. 




































GASOLINE AUTOMOBILES 275 

The surfaces of the valves are grooved at J to produce proper distribu¬ 
tion of oil. 

The Knight type of motor has been adopted by a number of 
well-known firms in America, such as the Stearns, Willys, F. R. P., 
Brewster, and Moline Companies. These engines are noted for 
their silent running and for their efficiency. The Moline-Ivnight 
motor was subjected to a severe continuous-run test of 337 hours, 
under the auspices of the A. C. A. authorities, in January, 1914. 
During this time the motor developed an average of 38.3 brake horse- 



Fig. 191. Sleeves Which Replaced Valves on Knight Engine, after 
137-Hour Bench Test and 2200 Miles on the Road 


power. During the 337th hour the throttle was opened, the motor 
developed a higher speed and a brake horsepower of 53. After the 
test, the motor parts showed no particular evidence of wear. The test 
gives abundant evidence of the endurance and reliability of the sleeve- 
valve type of motor and of the sterling qualities of the product of 
the American automobile manufacturers. 

In addition to the four-cylinder forms just mentioned, the 
Knight type of motor is also made as a six, and, more recently, as 
a V-type eight. In these forms, the basic principle of sliding sleeves 
and their method of operation and timing is not changed. 




276 


GASOLINE AUTOMOBILES 


Originally, the Knight motor was installed only in the highest- 
class cars. The firms in Europe which took it up ranked among 
the very first—notably the Daimler, Panhard, Minerva, etc.—but 
in this country it has made little progress among the better cars. 
It is now assuming the rank of a low- and medium-priced motor, being 
available for about SI000, and as an eight, for approximately $2000. 

Timing the Knight Motor. While the connection between the 
Knight motor sleeves and eccentric rods, and between the rods and 
the eccentric shaft, is more or less permanent, there is the possibility 
of the shaft being bent or twisted during running or dismounting. 
The repair man should know how the motor is timed, in order to cor¬ 
rect any faults. As will be noted 
in the timing diagram shown in 
Fig. 192, this is not radically 
different from the poppet-valve 
type. The inlet opens at 6| 
degrees past the upper center and 
closes 45 degrees past the lower 
center, a total opening of 218 \ 
degrees. The exhaust opens 40 
degrees before the lower center 
and closes 5 degrees past the 
upper center, a total opening of 
225 degrees. 

The various positions are clearly 
shown in Fig. 193, and make the 
action of the motor much more clear than the simple timing diagram. 
The figures, reading from the left, are as follows: 1 shows the inlet 
just beginning to open; the inner sleeve is coming up, and the outer 
sleeve is going down, so the port opening is increasing in area with 
unusual rapidity, ^t 2 the inlet is fulfy open; the inner sleeve-is 
coming up, but the outer has reached the bottom of its travel; the two 
ports are fully open and register exactly with one another and with the 
opening in the cylinder. At 3 the inlet has just closed, the inner sleeve 
is still coming up, while the outer sleeve has come up a considerable 
distance. A slightly further upward movement of both inner and 
outer sleeves shows the motor in 4, the top of the compression stroke, 
with all ports closed. 4 his is the point of explosion. In 5 the exhaust 


















GASOLINE AUTOMOBILES 


277 




Exhaust Opens 
Position 5 



Exhaust Open 
Position 6 



Exhaust Closes 
Position T 


Fig. 193. Various Stages in Cycle of Knight Sliding-Sleeve Motor 

i 


































































































































































































































































278 


GASOLINE AUTOMOBILES 


is beginning to open, the inner sleeve has reached the top of its move¬ 
ment and started down, while the outer is almost at the top. At 6 
the exhaust port is fully open, the slots register exactly with each 
other and with the cylinder outlet, both sleeves are traveling down, 
the outer having reached and passed its highest point. At 7 the 
exhaust has just closed, the inner sleeve has reached its bottom 
position and is about to start up, while the outer sleeve is close to the 
bottom. The cycle of inlet, compression, explosion, and exhaust 
has now been completed and is about to start over. Note that 
position 7 is almost exactly like position 1, but a slight additional 
movement of the sleeves is needed to produce the latter. 

The eccentric rods are very similar to connecting rods, as will be 
noted by referring back to Fig. 191. Here E is the eccentric rod 
operating the inner sleeve C , while D is the eccentric rod which oper¬ 
ates the outer sleeve B. As will be seen, these have an upper end 
exactly like a piston, or wrist pin, except that no bushing is provided. 
At the lower end, it will be noted that the fastening and arrangement 
is just like the big end of a connecting rod. It should be cared for, 
adjusted, and tightened in just the same way to get the best results. 

DETAILS OF ROTATING VALVES 

Successful Operation Requires Two Valves. In addition to 

rotating and reciprocating sleeves and reciprocating valves, the 
rotating valve has been tried, in common with any number of other 
devices intended to supplant the ordinary poppet valve. This 
arrangement on a multi-cylinder motor consisted of a single valve 
for all the cylinders, which extends along the top or side of the 
cylinder head and is driven by shaft, chain, or otherwise, at one end. 
Naturally, this necessitated having the ports cut very accurately in 
the exterior of the valve, or rather the sleeve—as it usually assumed 
the form of a hollow shell—for not alone did it act as inlet and exhaust 
manifold but also as the timing device. This multiplicity of func¬ 
tions seems to have been its undoing, for the latest types using 
valves of this form have no longer one shell as at first but a pair, 
one for the exhaust valves and one for the inlet valves. In the 
latter shape these have been more successful, but net sufficiently so 
to bring them into competition with the poppet and Knight sleeve- 
valve forms. 



GASOLINE AUTOMOBILES 


279 




Roberts Rotary I alve. A motor—a two-cycle motor, by the 
way which has been very successful in motor-boat and aeroplane 


Fig. 195. Rotating Inlet Valve of Roberts Two-Cycle Motor 

exhaust freely into the open air, the exhaust issuing directly from 
the cylinders. 

EXHAUST SYSTEM 

Importance of Handling Exhaust Gases Properly. In all that 
has been said previously on the subject of valves no mention has been 
made of a specific form of valve, everything applying equally to the 
inlet or the exhaust type. Under the subject of carburetors, the inlet 
manifold has been considered in detail. So far, nothing has been said 
of the exhaust gases and the method of handling them. Generally 
speaking, the matter of handling exhaust gases in the past has been 
done with the smallest possible amount of time, trouble, and thought. 
They had to be gotten rid of, so it was done as easily and quickly as 


work, although not much used for motor cars, is the Roberts, shown 
in Fig. 194, with the valve in Fig. 195. This valve is for the inlet 
ports only and is located inside the crankcase, while the cylinders 


Fig. 194. Roberts Two-Cycle Motor with Rotating Crankcase Valve 
Courtesy of E. W. Roberts, Sandusky, Ohio 



















280 


GASOLINE AUTOMOBILES 


possible. As engines got larger and larger, and as speeds increased, 
there was more and more gas to handle. The growing cry for a quiet 
or a noiseless car necessitated giving the problem more thought, for 
the simple application of a muffler did not entirely eliminate the noise. 
As fuels gre\v heavier, heat was required to assist in the process of 
vaporizing. In order to apply heat, many designers began to see 
possible uses for some of the gas pouring out at the rear end of the car. 
Today, the handling of the exhaust gases is probably being given as 
much thought as any part or unit on the entire car. 

Forms of Exhaust Manifolds. Ordinarily the exhaust gases 
emerge from the cylinders into the exhaust manifold. This is gen- 



Fig. 196. View of National Twelve-Cylinder Motor, Showing Particularly Exhaust Manifold 
Courtesy of National Motor Vehicle Company, Indianapolis, Indiana 

erally a cast-iron member of fairly large size held in position by bolts. 
At its rear end, which is round, it is threaded or flanged for the attach¬ 
ment of the exhaust pipe. This is shown rather well in the National 
engine in Fig. 196. Although this is a twelve-cylinder motor, it 


I 





GASOLINE AUTOMOBILES 


281 


has the outside valves, so the exhaust manifold is located there. It is 
a typical cast-iron manifold, differing from the ordinary manifold 
only in having the outlet at the center instead of the rear end. Six 
bolts hold it in place; four on the upper edge, and two on the lower. 
Its interior structure is evidently the same throughout, and no special 



provision has been made for reducing gas friction. It has no attach¬ 
ments of any kind. 

Many exhaust manifolds have been cast integral with the cylin¬ 
der block; this method is quite popular among small car makers, as it 
is used as much to save the expense of machining and fitting and to 













































































































282 


GASOLINE AUTOMOBILES 



reduce the weight and number of parts as for any other reasons. 
In the larger sizes it probably never will become popular, because of 
the difficult core work in the foundry which makes cylinder-casting 
cost prohibitive, and thus more than offsets any other saving. 

A number of manifolds have been cast with cooling fins, or flanges, 
on the outside, the effect being to reduce the exhaust heat immediately 
by dissipation; a secondary idea is that of making the casting stiffer 
and stronger and less liable to loss by breakage. A flanged manifold 


Fig. 198. Three-Quarter Rear View of Cadillac Motor in Chassis, Showing Exhaust Manifold 

and Pipes in Duplicate 

is shown in Fig. 197, which illustrates the Peerless eight-cylinder 
motor; the exhaust manifold is marked at A and B. The section 
taken at A shows the full exterior size; the boss, through which a 
holding bolt passes, is seen in elevation. At B, however, the section 
is taken through a pair of bolts, so the section appears smaller than it 
actually is. 

In the usual eight- and twelve-cylinder motor and in some sixes, 
a pair of manifolds, each with its own exhaust pipe and muffler, are 
used. It has been found by experience that the tremendous volume 








GASOLINE AUTOMOBILES 


283 



Fig. 199. Cadillac Chassis from Above, Showing Double System of Exhausting with Twin Mufflers 























284 


GASOLINE AUTOMOBILES 


of gas to be handled, the speed at which it had to be handled, and the 
necessity for silence called for a separate exhausting system for each 
group of cylinders. These were problems, aside from the fact that it 
was more simple structurally to handle the exhaust in two manifolds. 
A double-manifold construction is shown in the Cadillac, Fig. 198, 
which is a view of the rear end of the engine. The two manifolds 
for the two sides can be seen readily; also the two separate exhaust 
pipes, wrapped with asbestos where they pass the dash and other 
wooden parts. A further view of this car is shown in Fig. 199, the 
chassis from above, in which the two separate systems can be fol¬ 
lowed back to the mufflers just forward of the rear axle on either side. 

Muffler. The purpose of the muffler is to reduce the pressure of 
the gases by expansion to a point where they will emerge into the 
atmosphere without noise. This is generally done by providing a 
number of concentric chambers; the gas is allowed to expand from the 
first passage into the much larger second one, then into the still larger 
third one, and so on, to the final and largest passage, which is con¬ 
nected to the pipe leading out into the atmosphere. This is not as 
simple as it sounds, for, if it is not well and wisely done, there will be 
back pressure which will reduce the power and speed of the engine, 
cause heating troubles, and may possibly cause the motor to stop. 

The process of spraying water into the muffler has been tried, 
but on account of its first cost and lack of positive beneficial results, 
it has been abandoned. The actual construction of the muffler, 
however, takes a number of different forms. A number of forms are 
shown in Fig. 200. Baffle plates are used in the form at A, the gases 
being forced by them to expand from one chamber to the next so all 
the speed and pressure is dissipated before the outlet is reached. In the 
form shown at B, the gases are allowed immediate and sudden expan¬ 
sion from a comparatively small pipe into a large chamber. A series 
of annular chambers of large diameter but small depth forms the 
basis of C; the gas enters each of these chambers from the center 
through small holes, thence exhausting outwards, each chamber hav¬ 
ing an outlet around its circumference. In the form at D, the gases 
enter the central small pipe, escape through holes at its far end, which 
is blocked off, into the first concentric chamber where they travel 
to the front end where holes allow it to pass out into the second con¬ 
centric chamber and out into the atmosphere. This is a widely used 


GASOLINE AUTOMOBILES 


285 








Fig. 200. Five of the Many Different Types of Mufflers 
Courtesy of N. W. Henley Publishing Company, New York City 


Outlet 






































































































































































































286 


GASOLINE AUTOMOBILES 


type. Cone-shaped baffles which force the gases to expand and then 
pass through very small apertures and expand again form the basis of 
E. This is the so-called ejector type, the passage of the gases from the 
large to the small end of the various cones being supposed to create 
a suction behind it which draws the gas out from the exhaust pipe 
continuously. 

Muffler Troubles. When the engine mysteriously loses power, 
it is well to look at the muffler. A dirty muffler filled up with oil and 
carbon, which results from the use of too much oil in the motor, will 
choke up the passages so that considerable back pressure is created. 
When this is suspected, tap the muffler all over lightly with a wooden 
mallet, and the exhaust gases will blow the sooty accumulations out. 

Cut=Outs. Formerly, the majority of cars were equipped with 
muffler cut-outs. By pressing the foot on the button operating the 
cut-out, the engine was allowed to exhaust directly into the atmos¬ 
phere, cutting out the muffler. It served as a warning signal; it gave 
a good means of checking up the firing of the various cylinders; and 
several years ago, it was supposed to give greater power. Since its 
use was overdone, many cities and states prohibited such an arrange¬ 
ment on a car. Furthermore, the power loss has been proved a 
fallacy; consequently, the cut-out has gradually gone out of use. 

On six-cylinder motors, and particularly motors with more than 
six cylinders, the sound of the exhaust is not an accurate guide to the 
firing of the cylinders, except for the expert mechanic with unusually 
keen hearing. The explosions of the six-, eight-, and twelve-cylinder 
engine overlap to such an extent that the weak explosion between two 
healthy ones cannot be detected. A missing cylinder can be found 
in this way, but not one that is simply getting a poor or weak spark. 

COOLING SYSTEMS 

WATER COOLING 

Though nearly all successful automobile motors, as well as most 
other internal-combustion engines, are water-cooled, there is so 
much obvious fault to be found with this system of securing a result 
—involving first the generation of heat and then its waste by a com¬ 
plicated refrigerating system, instead of its utilization by converting 
more of the heat units into useful work—that it is scarcely credible 
that water cooling can persist indefinitely. 


GASOLINE AUTOMOBILES 


287 


Water=Jacketing. The first essential in water-cooling a motor 
is to provide the cylinders with water jackets, through which the 
cooling water is circulated in contact with the outside of the walls 
within which the heat is liberated. 

Water jackets are of two types, integral and built-up. The latter 
system of construction, though adding to complication and conducive 
to leakage, permits of lighter construction, besides diminishing the 
likelihood of hidden flaws in the cylinder castings, which, with cored 
jackets, are not likely to reveal themselves until they cause a break¬ 
down, perhaps after the engine has been long in use. 

Integral Jackets. With integral jackets, the usual system is to 
form the jackets by cores, in the founding, so that there are no open- 



Fig. 201. Detailed View of Cadillac Cylinder Chassis 


ings in the jackets except those for removing the core sand and wires 
and for connecting the pipes of the circulating system. In many of 
the best examples of motor design, however, the core Openings are 
left very large but with plane faces, and are closed by screwed-on or 
clamped-on plates, thus making the construction practically a 
compromise between the completely integral and the completely 
built-on jackets. 

For example, in such modern construction as that shown in 
Fig. 2, a large plate will be noted on the ends of the cylinders. This 
covers a tremendous core hole, by the use of which the internal 
construction of the water jackets is made practically peifect in the 
foundry. This also allows easy inspection and cleaning, the removal 
of the two end plates enabling a person to see right through the w ater 











288 


GASOLINE AUTOMOBILES 


jacket from end to end. This latter-day construction overcomes all 
objections previously raised against troubles with complicated water- 
jacket cores. A detail of this cylinder block, showing clearly the 
arrangement of the end plates, the water passages around the cylin¬ 
der bores, and other points, is presented in Fig. 201. The designers 
of large block castings for cylinders were forced to provide for easy 
inspection of this kind for self-protection, although in this connection, 
it is no more than fair to state that foundry men have made just as 
rapid advances in the art of casting automobile-engine cylinders and 
other complicated parts as the designers of machines have made in 
every other way. 

Built-On Jackets. There are a number of forms of built-on 
water jackets, but few of these are in use at present. The best of 
these was the old Cadillac jacket, a cylindrical one-piece member with 
a junk ring, top and bottom, to hold tightly against water leakage. 
The form more often used is the applied plate, or sheet, which must be 
held by screws, flanges, or clamps. As these are not really success¬ 
ful in holding the water continuously, particularly against the com¬ 
bination of hot water, internal pressure, twisting, and racking action 
which comes from traveling over bad roads at high speeds, they are 
giving way to the older form of jacket. 

An important advantage of applied jackets of the type just 
described is their freedom to yield in case the water freezes in them. 
The danger of cracked cylinders, which not infrequently results 
from exposure to cold weather in ordinary automobile motors having 
jackets integral with the cylinder, is eliminated. 

A particularly neat method of water-jacketing, which has been 
applied with some success abroad, consists in the electro-deposition 
of copper jackets on the cylinders, through the use of wax molds, 
to produce the desired forms. Jackets thus applied, though some¬ 
what expensive, are said to be practically indestructible and com¬ 
pletely proof against leakage. 

Welded Applied Jackets. The method of welding by the oxy- 
acetylene process promises to produce a cylinder with a cast-iron 
center and a sheet-metal water-jacket exterior made of pressed steel 
or of flat plates. The designers who consider this combination the 
best in that the thin sheet metal of copper or steel is lighter, radiates 
more heat, and will yield under freezing strains, will now be able to 


GASOLINE AUTOMOBILES 


289 


obtain such a combination at a reasonable cost. So far, however, 
it has been restricted to racing cars, in which the lightest possible 
weight is obtained regardless of cost. In a car to sell at an ordinary 
price, the cost might be prohibitive. 

Radiators and Piping. It has often been pointed out that all 
cooling of automobile engines is, in reality, air cooling; the water- 
cooled motor is simply one in which the heat units to be disposed 



Fig. 202. Horizontal Plate Type of Tubular Radiator Used on Studebaker Cars 
Courtesy of Studebalcer Corporation, Detroit, Michigan 


of are conveyed from the cylinders to the radiator by the circulating 
water, to be dissipated in the air that passes through it, instead of 
directly lost in air passing over thin flanges cast on the c}lindeis. 
A water-coolmg system therefore constitutes a soit of indirect-air 
cooling. This being the case, the chief justification for water cooling 
consists in the margin it allows for much greater cooling areas in 
contact with air than it is possible to provide b\ mere extensions of 
the cylinder surfaces themselves. 


























































290 


GASOLINE AUTOMOBILES 


A typical pleasure-car radiator of the tubular type is shown in 
Fig. 202. As will be noted, the flanges have a continuous horizontal 
appearance, but the vertical tubes which carry the water can be seen 
in the background. These actually carry the water; the horizontal 
flanges simply serve as a heat-radiating surface. This type is rapidly 
increasing in popularity for pleasure cars of medium and low price, 
at the expense of all others. 

The total cooling area of the radiators employed in automobiles 
will range all the way from ten to ninety square feet; the latter 


Section or Filler 



Fig. 203. Vertical Tubular Spiral Fin Type of Riker Truck Radiator with Cast Headers 
Courtesy of Locomobile Company of America, Bridgeport, Connecticut 


surface is not unusual in the best type of honeycomb radiators with 
hexagonal openings and very thin water spaces. 

The smaller areas are found in the cheaper types of radiators 
built up of straight, round, or flat tubes, and provided with fins to 
increase the area exposed to the air. Radiators of these types, unless 
very large, are often inadequate to cool a motor when it is laboring 
under continued heavy usage, as in pulling on the low gear through 
deep sand or mud or up long heavy grades. Under such conditions, 






















































































































































































































































































GASOLINE AUTOMOBILES 


291 



a motor that may have run for months without any cooling trouble 
w hate\ er in level country will often boil all the water out of the 
cooling system within a few minutes. 

Types of Cells. In the cellular, or honeycomb, radiator, there are 
three forms of tubing in general use. These forms are: the square, 
with its flat sides set horizontally and vertically; the round, with the 
tubes staggered so as to make the number as large as possible; and 
the hexagon, which is also set staggered so as to use the maximum 
number. The square and hexagon are more used on pleasure cars, 


Fig. 204. Renault Form of Radiator Situated Back of Engine 

while the round form has been used on higher-priced motor trucks. 
A modification of the round-tube form is found in the radiator which 
utilizes the plain copper tubes, bunched and fitted into a header, or 
water tank, at the end, but which are not formed into a composite 
unit. This is used on both pleasure cars and trucks. 

Types of Tubes. In the tubular form, there are two well-known 
types: the round vertical tube with spiral fin, or flange, w r elded or 
sweated on; and the so-called tube-and-plate construction, shown in 
Fig. 202, in which a set of horizontal plates is pierced with a number 






292 


GASOLINE AUTOMOBILES 


of holes, tubes set into these, and the whole dip-soldered into a unit. 
The former type is gaining rapidly for truck use on account of its 
freedom from leakage under the severe racking conditions of truck 
use. An example of this type is to be found in Fig. 203, which shows 
a welded tubular radiator. It is of interest to note that the welded 
type replaced a soldered honeycomb unit of the highest quality which 
could not be kept water tight in war service. 

Modifications of Cellidar and Tubular Forms. In addition to the 
types shown in Figs. 202 and 203, there are a number of forms which 




Fig. 205. Outline of Coiled Copper Tube Radiator Used on International Trucks 

partake somewhat of their characteristics, but which show a marked 
individuality. The Renault form, which is placed at the dash instead 
of at the front, is shown in Fig. 204. It has a tank at the top and 
small tanks at the bottom and sides, the central bottom space being 
taken up by the fan. The tubes are of pure copper and are not 
fastened together as in the cellular radiator, but merely connected 
at the two ends. As compared with the average radiator of the 
cellular type of equal cooling capacity, this form requires greater height, 
width, and depth. Its dash position has the disadvantage of keening* 
the driver’s compartment uncomfortably hot in the summer months. 

























































































GASOLINE AUTOMOBILES 


293 


Another modification along somewhat similar lines, which is used 
for a truck, is that shown in Fig. 205. This form consists of an upper 
tank, a small lower tank with the outlet, and a connecting group of 
copper tubes. It is made in the form of a circle of the largest possible 
diameter the tube structure will allow and of a width equal to the 
depth of the bank of tubes. The fan is placed in its immediate 
center. By placing the radiator at the rear end of the engine, the 
fan can be driven directly from the crankshaft or the flywheel, which 
gives the fan a higher speed. The unusual size and high speed of the 
fan circulates an unusual amount of air around the bare copper tubes. 
Copper is the best radiator of heat known except silver. On a truck, 
the position of the radiator at the back of the engine is held to be 
a big advantage, because the 
entire cooling system is protected 
from the frequent and unavoid¬ 
able collisions of truck service. 

The piping of automobile 
cooling systems in a great many 
cars is made too small to afford 
free circulation, and this mistake 
in design, common in the earlier 
days of automobile engineering, 
is one that cannot be too carefully 
avoided. 

In the experience of most 
automobile designers, the most satisfactory method of connecting 
up the piping of a circulating system is found in the use of ordinary 
steam hose, clamped around the ends of the pipe by small metal 
straps. 

The use of steam hose for practically the entire piping system 
is considered an improvement over the short hose connection by a 
few designers. It does, away with metal piping altogether except as 
it extends from the radiator and water jackets for the attachment of 

the hose. 

Circulation. An unobstructed and vigorous circulation of the 
water in a cooling system is a great factor in reducing the size of 
radiator required and in preventing overheating and boiling away 

of the water. 







294 


GASOLINE AUTOMOBILES 


Pumps. The usual method of circulating the cooling water is 
to use one type or another of small pumps, driven by suitable gearing 
from the engine itself. 

Gear pumps are often used for this purpose because of their extreme 
simplicity, but it is difficult to make them large enough to handle 
as great volumes of water as most designers now regard desirable. 

A good example of the gear form of water pump is shown in 
Fig. 206. This is simply a pair of gears which mesh rather closely; 
the movement of the flat side of the teeth carries or forces the water 



forward. In general, the gears are made of small diameter but wide 
face to take advantage of this action. The result is a very compact 
pump. The vane type of pump is really a modification of the gear 
pump in that a rotating member is placed in an eccentric chamber 
with a sliding arm on either side, which is held out into contact with 
the sides of the chamber by a central spring. This double sliding 
arm simulates the effect of the teeth of the gear form. This has small 
capacity and is not widely used on that account. 

The consequence is that the centrifugal pump is now the type 
most preferred. In their best forms, centrifugal pumps consist of 

















































































































GASOLINE AUTOMOBILES 


295 


simple multi-bladed “impellers” revolving with close clearances in a 
housing. 

One advantage of the centrifugal pump is that if any small 
object, such as a stick or pebble, should by any chance get into the 
circulating system—though strainers always should be provided to 
prevent this contingency—no serious harm is likely to result, whereas 
with a gear pump breakage is almost certain to ensue. 

The construction of the centrifugal form can be seen in Fig. 207. 
This is not as clear as it might be because the impeller is sectioned at 



Fig. 208. Thermosiphon System of Cooling as Used on Overland Cars 


the point where the water chamber is largest; in short, at the water- 
outlet space. The impeller fits the casing very closely except at 
the w r ater outlet where the water is thrown off by the centrifugal 
force generated in rotation. The centrifugal form of pump is also 
fairly well illustrated in Fig. 210, where it will be noted that two of 
them are used on the two ends of the upper shaft. 

Chiefly in motor-boat motors of the two-cycle types, recipro¬ 
cating plunger pumps are used to circulate the cooling water. The 
volume of water handled by pumps of this type, of dimensions that 
can be conveniently employed, is not very large, however, and it is 































































































































296 GASOLINE AUTOMOBILES 

/ 

only the fact that the water is not re-used and is, therefore, cooler 
and of a consequently greater effectiveness that makes possible the 
use of plunger pumps in motor boats. 

Thermosiphon. Circulation of the cooling water by the thermo¬ 
siphon action, owing to the heated water in the jackets rising and the 
cooled water in the radiator descending, is the practice of an increas¬ 
ing number of designers, and has been demonstrated to be very 
effective with liberal jacket spaces and large-diameter piping. 

The pioneer, and still the most prominent exponent, of thermo¬ 
siphon cooling is the Renault Company, of France. A typical 
Renault motor-and-radiator combination with thermosiphon cir¬ 
culation is illustrated in 
Fig. 204. 

A better example of 
the thermosiphon sys¬ 
tem, that is, a drawing 
which shows it much 
better is Fig. 208. In 
this the large open pipes 
with few bends, and 
those few very easy so as 
to reduce water friction 
to a minimum, are well 
shown, also the small 
difference in level be¬ 
tween the top and bottom of the system. The difference in tempera¬ 
ture causes the movement of the water. It is said that the pressure 
which the temperature variation produces is seldom more than a 
small fraction of a pound; for this reason it is necessary to reduce 
surface friction and losses at bends and at other similar points. 

Cadillac System. An entirely new idea in the control of the 
temperature of the cooling water is that used on the new eight- 
cylinder Cadillac motors. Here, each block of four cylinders has its 
own circulating system, with pump and piping, entirely distinct from 
the other. In each one a thermostat, like that shown in Fig. 209, is 
located on top of the pump housing. This controls the movement 
of a valve, which, when shut off, prevents the flow of water to the 
radiator, that is, when the temperature of the water falls below a 



Fig. 209. Thermostatic Device in Latest Cadillac Water- 
Cooling System to Preserve Equilibrium and 
Even Temperature 























































GASOLINE AUTOMOBILES 


297 


certain figure at which the thermostat is set, it comes into action and 
cuts off the flow of water from the radiator to the pump. The result 
is that the pump can circulate only that part which comes through 
the very small pipe to the inlet manifold and carburetor and from 
there back to the pump. This continues until the water becomes 
heated; the raising of the temperature operates the thermostat which 
opens the valve, and the system is again complete. In the upper 



Fig. 210. Thermostat and Water-Pump Group on Packard Twelve-Cylinder Motor 
Courtesy of Packard Motor Car Company, Detroit, Michigan 


right-hand part of this figure, the circulating system of one block of 
cylinders is shown in outline. 

The method of controlling the temperature of the engine with 
an automatic check valve is receiving much attention; there is even 
talk of extending the same system of control to the exhaust gases and 
all sources of heat, interconnecting them with the fuel vaporizer so 
as to vaporize the maximum amount of fuel in the minimum time with 
the least heat loss. The thermostat and pump combination used on 
the Packard twelve-cylinder motor is shown in Fig. 210, in which it 
will be seen that two pumps are placed on the pump shaft, one at 
































































































298 


GASOLINE AUTOMOBILES 


each end so that the thrust of each one balances the other. In the 
Cadillac, the two cylinder groups are separate, each having all the 
units shown in Fig. 209 except the radiator. In both the Cadillac 
and Packard systems, the thermostat is placed at the bottom of the 
system. It has been advocated by engineers for other companies 
that this would do the most good if placed at the top of the system. 

The value of a thermostat may be gained from these figures. 
One particular make of thermostat, as used on a popular make of car, 
was tested out with the following results: Without it, the car did 
14| miles on a gallon of fuel at 15 m.p.h. and 13J miles at 30 m.p.h. 
At the same speeds and with the thermostat set at 160 degrees, 
the same car under the same circumstances did 16| miles at 
almost 15 m.p.h. With everything the same but with the device set 
to work at 180 degrees, the car did 19J and 16J miles, respectively. 
The gain at the lowest speed of 15 miles an hour from 14| to 16J and 
then to 19| miles per gallon represents gains of almost 14 and 38 
per cent in economy. 

Fans. In the earlier days of automobile designing it was 
deemed sufficient to secure circulation of air through the radiators 
by the movement of the car alone. This was soon found inadequate, 
however, for often when most cooling was needed, as in hill climbing 
or hard pulling on the level, the car would be moving at its lowest 
speed on low gear, with the result that the air draft through the radi¬ 
ator was not sufficient to cool the water. 

This condition was remedied by the use of a fan behind the 
radiator, driven by a belt or gearing from the motor so as to draw 
a constant draft through the radiator in proportion to the speed of 
the engine rather than of the car. 

Nowadays, practically all automobile power plants are provided 
with fans, the only exceptions being a few very small motors in which 
the difficulty of cooling is not so great as with the higher powers. 

In some cases, instead of a separate fan,, fan blades are placed 
on the flywheel, and so made to induce a draft through the bonnet 
that covers the engine, thus avoiding the necessity for the addition 
to the moving parts involved in the usual fan system. Such a fly¬ 
wheel fan is used in the engine illustrated in Fig. 204. 

A later plan of even greater effectiveness is the housing-in of 
the whole rear end of the radiator, so that what air passes through 




GASOLINE AUTOMOBILES 


299 


must pass through the center where the fan is located. This is but 
another way of saying that all air must pass through at a high 
velocity, which insures efficiency. This plan fulfills one requirement 
of air cooling, that is, the large quantity of air which must be used. 

Where this system is used now, the entire engine in front of the 
fan is made air tight. The hood, which has no openings anywhere, is 
set into carefully fitted rubber strips to cut off any possible leakage. 
The same precautions of drawing all the air through the radiator, 
and through that alone, are observed elsewhere. While this method is 
effective, it is a disadvantage in another way, for some direct cooling 
is effected through the cylinder walls, exhaust pipes, etc., in the 
ordinary system by the cold air passing over the radiator, particularly 
the air which comes in from around the hood top and sides. 

Anti=Freezing Solutions. In using automobiles in very cold 
climates during the winter months, there is great danger of the water 
in the cooling system freezing when the car is standing still, or even 
with the motor running slowly if the temperature is very low. The 
result of such freezing is almost certain injury to the cylinders, 
through cracking of the water jackets, as well as the probability of 
bursting out radiator seams, with consequent leakage. 

To avoid these difficulties it is not uncommon to use, instead 
of pure water, one kind or .another of anti-freezing solution, usually 
compounded by the mixture of some chemical with water to lower 
its freezing point. Thus, glycerine or alcohol mixed with water will 
keep it from freezing at all ordinary winter temperatures. Glycer¬ 
ine is somewhat objected to because of its sticky, gummy nature, and 
also because of its deleterious effects upon the rubber hose of the 
piping system. Alcohol, if not replenished from time to time, will 
evaporate out of the water and thus permit it to freeze, or, if mixed in 
too great a quantity, it may introduce a fire risk otherwise avoidable. 

A much favored anti-freezing solution consists of calcium 
chloride dissolved in water, in a quantity proportioned to the tem¬ 
peratures that it is desired to guard against. 

All anti-freezing solutions are more or less objectionable in that 
they are more likely than pure water to corrode and clog up the cir¬ 
culating system, and there is no doubt that the elimination of the 
necessity for them by the substitution of an cooling for water 
cooling will mark a great advance in automobile development. 


300 


GASOLINE AUTOMOBILES 


AIR COOLING 

Though successfully employed in one or two automobiles and 
remarkably developed in some of its applications to aviation motors, 
air cooling is not considered by most engineers to be successfully 
applicable to the average automobile. That it will become more 
practical in the future, however, is the opinion of many. 

Unfortunately, this is an instance where the better and simpler 
method does not meet with popular approval, that is, the cooling 



Fig. 211. Diagrammatic Illustration Showing System of Air Cooling on Franklin Cars 
Courtesy of II. II. Franklin Manufacturing Company, Syracuse, New York 


of automobile cylinders is one of those cases in which the best in 
theory is not, by any means, accepted practice. The extent to which 
the public has adopted water cooling as compared with air cooling 
may be noted in these figures for 1916: Cooled by air, 1 car; cooled 
by water, 168; total, 169. 

Flanges, or Fins. The usual method of air cooling, successfully 
employed in aviation and motorcycle motors and in a few automo¬ 
biles, is to provide the cylinders with fins, or flanges, for increasing 
the area of the surface, supplementing this with means for blowing 
large volumes of air over the surfaces thus provided. 













GASOLINE AUTOMOBILES 


301 


Air Jackets. Several of the most practical examples of air¬ 
cooled motors in aviation construction are those which have, in 
addition to the flanges, or fins, on the cylinders, air jackets to concen¬ 
trate the drafts of air that effect the cooling. 

Blowers and Fans. The most successful air cooling has been 
accomplished by types of blowers capable of inducing much more 
vigorous air currents than are drawn through the radiators of water- 
cooled automobiles by the types of fans commonly used in power 
plants of that character. 

In the Franklin, the most successful air-cooled automobile 
motor, a side view of which can be seen in Fig. 211, the cooling is a 
sort of combination of the flange and the blower method. The fins 
are vertical and radial, with a close-fitting hood connected to an air¬ 
tight pan. At the only opening in this hood, which is at the rear end, 
is placed the fan (on the flywheel). This draws the air past the 
cylinder walls, where it is needed. 

Internal Cooling and Scavenging. Perhaps more promising as 
a road to final and universal use of air cooling are the systems of 
pumping air through the interiors, instead of blowing it over the 
exteriors, of the cylinders. Such internal cooling, in addition to 
directing the maximum cooling effect where it is most needed on 
the oil-coated surfaces that are exposed to the heat of combustion, 
has the further advantage that it may be made to scavenge out all 
residual exhaust gases, which, besides helping to accumulate heat, 
also act so detrimentally upon the functioning of ordinary motors. 
This is a direct result of the admixture of retained exhaust gases 
with incoming fresh charges. 

Methods of internal cooling and scavenging that appear of 
definite promise are those proposed in various recent schemes for 
pumping air first into the crankcase—either by using the under side 
of the piston as a pump, as in common two-cycle constructions, or 
by applying special pumps to the crankcase for this particular pur¬ 
pose—then into the cylinders by means of by-passes, with the result 
that it exerts a positive cooling effect inside the cylinder. 

In England, some interesting experiments have been made on a 
theory of internal cooling in which water is introduced into the 
cylinders in the form of a spray, at certain points in the cycle. This 
is said to add power in addition to helping the cooling. 


202 


GASOLINE AUTOMOBILES 


COOLING TROUBLES AND ADJUSTMENTS 

Cleaning. It is highly important that the cooling system be 
entirely cleaned out at least once, and preferably twice, a year. When 
this is done, the water jackets and radiator should be flushed out with 
a strong current of water, preferably a hot soda solution. This should 
be forced through in a direction opposite to the usual course of the 
water. Thus, a hose can be put in the radiator filler cap and city 
pressure applied to force the water through; in this radiator, it will be 
made to go from bottom to top instead of the usual top to bottom. 
If this method, which is the usual and easy one, does not remove all 
dirt, sediment, and foreign matter, the radiator can be removed and 
boiled, or at least submerged, in a strong soda solution which will 
clean it out thoroughly. The radiator is the most important member 
of the system. 

Replacements. When this is done, it is advisable also to look 
over all hose and hose connections. Many times the hose will have 
become worn or frayed through and cut or otherwise damaged from 
the outside, or the water may have attacked it from the inside, par¬ 
ticularly if it has been through a winter when an anti-freezing 
solution was used. It is well, when cleaning the system, to replace all 
hose with new. The clamps are important as they determine the 
water tightness of the hose, so they should be looked over for missing 
nuts, broken screws, broken clamp ends, as well as to note if each one 
is applied straight and true over the hose and the end of the pipe on 
which it is placed. 

Washing. If the radiator is splashed with mud or dirt, the 
washing should be done from the rear, with the hood removed. This 
method allows free use of the hose, and at the same time it insures 
against getting any water in the ignition system where it would cause 
trouble. 

Adjusting=Fans. Usually, the fan is hung on an eccentric bushing 
held in a clamp. It is important that the fan belt be tight enough so 
that there is no slippage, otherwise the engine will heat up. To 
tighten a belt, loosen the clamping bolt on the fan eccentric, and then 
turn this eccentric so as to move the fan-shaft center away from the 
crankshaft-pulley center. The eccentric may be moved with the 
hands, in some cases; in others, a wrench is provided, and the fan 
eccentric made with surfaces on which the wrench fits; while still 


GASOLINE AUTOMOBILES 


303 


others need the application of a pointed tool and hammer to turn 
it. In the latter case, do this very carefully so as not to chip off 
any metal. Occasionally, the fan bearings need adjustment or lubri¬ 
cation. When they are of the plain type, a grease cup is generally 
provided, and after the engine is stopped, a couple of turns of this 
will be sufficient. If of the ball or roller type, they will be packed in 
grease, and if they show signs of running dry, the fan should be taken 
apart and the grease renewed. Use a good grade of cup grease for 
this purpose, not a hard grease. 

Adjusting Pumps. Generally, the pump is made so as to need no 
adjustment. However, a leak may occur at one of the packing nuts. 



To remedy it, tighten the nut as far as possible, but if this does no 
good, remove the nut and add packing under it. Special packing is 
provided for this purpose, but if no other is available, a thick heavy 
piece of string can be well coated with graphite or a graphite grease 
and wound on as packing. In putting on packing of this kind, it 
should be wound on rightlianded, or in the same direction as the pack¬ 
ing nut turns to tighten. Otherwise, tightening the nut will loosen 
the packing. 
























































304 


GASOLINE AUTOMOBILES 


The Ford motor circulation is of the thermosiphon order, but 
often, for one reason or another, it does not do well, so the motor con¬ 
tinues to heat, although everything appears in good condition, fan 
belt tight, etc. For such cases, an additional means of circulating 
the water is needed. There are several devices on the market, one 
consisting of a form of screw set into the water pipe with the idea of 
stabilizing the flow of water. Another, Fig. 212, uses the force of the 
exhaust gas by-passed through a small special pipe into a nozzle 
of the ejector type placed in the water inlet to cylinders to make 
the water flow more rapidly and evenly. It is said that this uses but 
3 per cent of the exhaust gas and that it is designed to keep the 
water system working at 195 degrees, which is a very efficient point, 
more power being developed at temperatures approaching the boiling 
point than at low temperature. In addition to improving the water- 
circulating system, this device is said to eliminate carbon formation 
and save 20 per cent of the fuel and oil. 

In general, the cooling system is an easy one to take care of and 
repair because such a large part of its units and components are fool¬ 
proof. Moreover, it is a system which gives visual and other evi¬ 
dences of derangement. 

Summary of Cooling Troubles 

Anti=Freezing Solutions. The following are satisfactory formulas 
for anti-freezing mixtures: 

1. Mix equal parts of glycerine and water. Replace evaporation 
with clean water. Replace leakage with fresh solution. 

2. Mix equal parts of denatured alcohol and water. Replace 
evaporation with alcohol and replace leakage with solution. 

Radiators. Radiators must be kept well filled. Leaky radiators 
are difficult to repair. This work should be done by an experienced 
radiator man, never by a plumber. 

Soft Water. Soft water should be used for filling tank. It 
should be borne in mind that the circulating water gets pretty hot, 
and that incrustation may result from hard water. 

Engine Heats, Loses Power, and Knocks. These are all symp¬ 
toms of lack of water circulation. To see if this is the case, look into 
the opening in the top of the radiator and see whether water is flowing 
.in from the engine. If not, either the water-piping system is stopped 


GASOLINE AUTOMOBILES 


305 


up, which can be checked by disconnecting, or else the circulating 
pump is not working properly. All modern engines are so propor¬ 
tioned that, in this event, the water continues to circulate by thermo- 
siphon action. Taking off the pump will verify this. 

LUBRICATION SYSTEM 

MOTOR LUBRICATION 

When the lubrication system is referred to, that of the motor is 
generally meant. Motor lubrication is of the highest importance; 
for the motor must have efficient and continuous lubrication to run 
properly. Taken in its broadest sense, however, the title should refer 
to the entire lubricating means of the car; that is the way it will be 
handled here. The other units and parts of the car may not need as 
efficient or as continuous means of lubrication as the engine, and the 
presence or lack of lubricant is not so tremendously important; but all 
of it is of value and influence in the operation of the car, and should 
be well known. 

Interior and Exterior Demands. The engine of a motor car 
requires two distinct kinds of lubrication. The interior parts, which 
are subjected to the greatest heat, rotate or slide at the highest 
rate of speed, and generally do the greatest amount of work, must 
have what amounts to a continuous stream of good lubricant. With 
the exterior parts, which do not rotate so fast, do less work, are not 
subjected to much heating, and will be kept cool by the atmosphere, 
there is no need for this continuous stream, nor for such a quantity 
or high quality of lubricant. 

The exterior and interior systems must be considered sepa¬ 
rately. With reference to the internal oiling, there are two general 
systems in use: the pressure form, and the splash type. A third, which 
is now coming rapidly into use, is a combination of the two, called the 
splash-pressure system. For 1917, the relative popularity of these 
three is as follows: pressure, on 30 per cent; splash, on 35; splash- 
pressure, on 35. 

In the pressure form (or its modification, the splash-pressure), 
the pressure may be produced in a number of ways: by a single large 
pump; by a series of small pumps, one for each bearing lead; or by a 
reservoir, or tank, kept filled by a separate pump (gravity pressure). 


306 


GASOLINE AUTOMOBILES 



Splash=Pressure Feeding. One of the best and most successful 
types of lubrication systems is that in which the oil is fed under 
pressure to the different bearings. 

In the splash-pressure system, the oil to all the crankshaft and 
connecting-rod bearings, to the timing gears, and to the upper portion 
of the cylinder walls is supplied through the medium of a gear-oil 
pump driven usually by worm gearing from the camshaft. The other 
bearings within the engine are lubricated by oil spray thrown from 
the crankshaft. Such a system is shown in Fig. 213. 

Overland . The same units are necessary in all splash-pressure 
systems, but they can be and are used in widely different ways. It 


Fig. 213. Pressure-Feed Lubrication System on Pierce-Arrow Cars 
Courtesy of Pierce-Arrow Motor Car Company, Buffalo, New York 

is of interest to the repair man to know the details of a number of 
these methods so as to be able to repair and adjust the mechanisms 
more readily, also to more quickly point out their troubles. One of 
the most simple systems in use is that of the Overland, as shown in Fig. 
214. In this, the oil pump at the bottom of the oil sump A is driven 
from the camshaft rear end. After passing through the strainer B, 
the oil continues through an outside pipe to the sight feed C on the 
dash. This simply indicates that the system is working continuously. 


























GASOLINE AUTOMOBILES 


307 


From here it passes back through the pipe D to the inner distributing 
pipe E; this serves to keep the troughs FF, filled. At the middle part 
of the downward stroke, the scoop on the bottom of each connecting 
rod dips into its own oil reservoir and splashes up a fine spray of oil. 
At high speeds, the four rods fill the whole interior of the crankcase 
and the lower parts of the four cylinders with a mist of oil. This is 
sufficient to lubricate everything thoroughly. In a system of this 



Fie 214. Constant Level Splash System on Overland, in which Pump Maintains 

Oil Supply at Predetermined Level 

kind, the strainer is of great importance and must be kept clean. 
Similarly, the oil sump should be drained very frequently, at least 

every 1000 miles. 

Studebaker. The Studebaker system is very similar, except that 
the oil pump is outside of the crankcase and set higher up. It is of 
the simple gear type and is not liable to derangement. I he system 
is equipped with an oil-level indicator on the side of the case, which 
shows the quantity within the case. 













































































































































































308 


GASOLINE AUTOMOBILES 


SingIe=Pump Pressure Feeding. The drilled crankshaft, as 
shown in Fig. 213, is a necessity in all pressure systems, as it also is 
in all combination splash-pressure systems. This can be seen, and 
perhaps the whole system explained more clearly, by referring to 
Fig. 215. In this the single pump working direct is used, thus differ¬ 
ing from the reservoir system explained above. This diagram shows 
also how the oil is forced to flow through the three bearing leads to 



Fig. 215. Lubrication System of Cadillac Eight, Showing Pump and Path of Oil, Also 

Auxiliary Circuit for Crankshaft 


the interior of the crankshaft, whence it follows in to the pins upon 
which the connecting rods work. These rods are drilled, and the oil 
is thrown out by centrifugal force, passing up through the rods to the 
piston, thence onto the cylinder walls. In addition, the latter are 
sure to receive sufficient lubricant, for the rotating shaft and rods 
throw off a good deal in the form of a mist which settles upon the 
cylinder walls. 














GASOLINE AUTOMOBILES 


309 


Generally, pockets are provided inside the motor to catch the 
mist and force it to flow to the camshaft and other bearings besides 
the crankshaft, but in this case it will be noted that the camshaft 
bearings have individual supplies through the medium of a camshaft 
oiling pipe. 



Fig. 216. Pressure Lubrication System Used on Stearns-Knight Motors 
Courtesy of F. B. Stearns Company, Cleveland, Ohio 


An objection to lubricating systems of this type is that in case 
there are several leads to different bearings one of them may become 
obstructed without anything to indicate this condition or to over¬ 
come it until the bearing involved becomes overheated and ruined. 
If one lead becomes obstructed, the oil can still continue to feed out 





































































































































































310 


GASOLINE AUTOMOBILES 


through the others, thus relieving the pressure in apparently the 
normal manner and failing to reveal a serious derangement. 

Stearns. The Stearns-Knight system is shown in Fig. 216. 
The oil is circulated by a pump (not visible in this sketch) at the 
front end of the eccentric shaft D. After passing through a screen 
and the pump, it is forced through a strainer A in the filter E, thence 
through pipes to the pump-shaft bearings, eccentric-shaft chains, 
and main crankshaft bearings. It reaches the crankshaft bearings 
through the oil inlet F, the drilled holes in the crankshaft being indi¬ 
cated at G. From these holes, it reaches the hollow center of the 
connecting rods H, and thus to the piston pins and piston outer walls. 
At the bottom of each connecting rod, there are three small radial 
holes through which sufficient oil escapes to lubricate the inner and 
outer sleeves which take the place of the valves. A gage on the dash¬ 
board, or cowlboard, indicates the oil pressure and should read from 
1 to 5 pounds with the throttle closed and the motor idling, and 
from 40 to 60 pounds when the throttle is wide open and the motor 
running normally or at high speed. 

Regulator Connected to Throttle. The variation on this pres¬ 
sure is controlled entirely by the by-pass in the main oil lead, which 
is connected directly to the throttle-control mechanism. This by¬ 
pass consists of a body with an oil port and a piston with a series of 
holes. When the throttle is closed, and the motor idling, these holes 
and port register, so oil passes through freely, relieving the pressure 
on the bearings. When the motor is speeded up and more oil is 
needed, the piston is turned by the throttle connection so that the 
holes and ports no longer register and the oil cannot escape as freely and 
must be forced through to the bearings. This by-pass is adjustable 
by means of the small blade B , Fig. 216, which is rotated from the 
center to right or left and locked by the clamp bolt C. The safety 
valve I within the crankcase is set at the factory for the maximum 
pressure to be used in the system. If this is approximated, this valve 
is forced open and the oil escapes back into the crankcase, thus lower¬ 
ing the pressure. The oil-level indicator J is operated through the 
float K in the oil well and indicates the quantity. In cleaning and 
replacing filter screen A, be sure the holes register. The system used 
on the Stearns-Knight eight-cylinder V-type motor is essentially 
the same, with a few differences of location due to the form of engine. 


GASOLINE AUTOMOBILES 


311 


On high-speed and multi-cylinder motors (which are almost 
invariably high-speed forms), the lubrication assumes an importance 
not hitherto attached to it. This is responsible for the pressures used 



and for the wide spread use of mechanically driven positive pumps. 
Formerly, pressures of from a few ounces to 4 or 5 pounds were con¬ 
sidered sufficient. Now, pressures as high as 60 and 70 pounds are 
not unusual. These tremendous pressures, however, have necessi- 




















































312 


GASOLINE AUTOMOBILES 


tated a system much more carefully constructed, assembled, and used 
than was the case previously. 

Marmon. The Marmon system is not radically different from 
that just described, but there are a number of small individual points 
worthy of mention. The filling is not through the usual crankcase 
breather pipe, but through an opening in the top of the cylinder head 
1, Fig. 217. From this opening the oii flows around the valve push 
rods (the motor had overhead valves as will be noted) down into the 

bottom of the oil pan 2. After 
screening at 3, it passes 
through the throttle-controlled 
regulator to the oil pump 4 on 
the rear end of the camshaft. 
The main feed pipe is marked 
5, the pressure gage 6, lead to 
crankshaft bearings 7, hollow 
in crankshaft 8, connecting-rod 
bearing 9, cylinder walls 10, 
ball check valve 11 to govern 
pressure in main feed pipe 
and excess oil through hollow 
rocker-arm shaft 12, connect¬ 
ing to oil container 13 above 
valve tappets. 

In Fig. 218, a detail of 
the regulator is shown. Oil 
enters the pump body from the 
left through the opening B. 
The passage from B to the gears is controlled by the opening in the 
plunger A, which is operated by the movement of the throttle lever 
through the small tappet seen on top. When the throttle lever is 
depressed, the plunger moves down, and its upper, or piston, portion 
closes off a portion of the oil hole, restricting the supply. The spring 

■ . i£. if,, i. . 

under its lower extension is used to return it to position. Its shape 
is such that the oil has no tendency to act upon it, either to open or 
close it. In this system, the pressure varies from 12 to 60 pounds. 

Types of Oil Pumps. There are but three or four types of oil 
pumps now in use, these being the gear, plunger, plunger operated by 



Fig. 218. Detail of Throttle-Connected Plunger 
in Marmon Oil Pump 



































































GASOLINE AUTOMOBILES 


313 


/?e/ief 

Check Valve 



Fig. 219. 


Gear Type of Oil Pump of Marked 
Simplicity 


a cam, and in a few cases the vane pump. While essentially the same 
as the forms used for pumping water described previously, they are 
smaller in actual size and have some few different details. In the gear 
form, which is shown in 
Fig. 219, one gear is driven FJ13HI 

directly from the engine and, 
in turn, drives the other, 
their rotation forcing the oil 
along in the direction of 
rotation. Usually a by-pass 
with a check valve is pro¬ 
vided, and when the pipe 
is obstructed or the pres¬ 
sure rises for any other rea¬ 
son, this opens and the oil passes around the pump at low pressure, 
equalizing the system. 

The cam-operated plunger form is shown in Fig. 220. This is 
the method of drive adopted for mechanical lubricators, but few 
engines have an individually con¬ 
structed pump of this type. It is 
simple, easy to regulate, seldom gets 
out of order and can be arranged to 
give a different supply at each plunger 
should the system warrant or necessi¬ 
tate this. A good example of the 
plunger form is the oil pump on the 
Reo engine, shown in Fig. 221. This 
works as follows: When the pump 
plunger A is moved upward by the 
curved eccentric B, it draws oil through the ports C and the screen 
D, as the entire lower part is submerged in the oil. When the max¬ 
imum amount of oil is drawn into the pump chamber in this way, the 
plunger descends, the ball E rises, and the oil flows up inside the 
hollow plunger to the top ports F, through these to the surrounding 
chamber G, and thence to the outlet H and into the oil pipes. This 
form is very accurate and reliable. 

Methods of Driving Pumps. Another point of considerable 
importance to the repair man is the method of driving the pump, 


Yfor/n Gear 


Worm 



Oaf/e! 
Check Valve 


Pump Cylinder 
Pump Plunger 


Worm Drive Chaff 
/rrlef Check Valve 


Fig. 220. Cam-Actuated Plunger 
Form of Oil Pump 



















































314 


GASOLINE AUTOMOBILES 



since this influences its location and its accessibility. There are but 
two general methods of driving. One is by means of a special oil-pump 

shaft, in which the pump will 
quite generally be found in the 
bottom of the oil sump or very 
close to it; the other is from 
some part of a shaft used for 
other purposes, in which case 
the position may vary widely. 
Examples of the first, or special- 
shaft method, will be seen in 
Overland, Fig. 214, and Cad¬ 
illac, Fig. 215. Examples of 
the second method are seen in 
Stearns, Fig. 216, and Marmon, 
Fig. 217, in both of which the 
camshaft is used. 

In Fig. 222, a gear is placed 
directly upon the rear end of 
the camshaft meshing, with 
another immediately below it 
which forms the pump. This 
is the Scripps-Booth eight. 
Attention is called to these 
additional points, the hollow 
crankshaft for oil circulation 
at A, the method of carrying 
the oil leads and regulator up 
to a handy point on top of the 
motor at B, and the air cooling 
flanges on the bottom of th<e oil 
pan at C. The purpose of the 
latter is to reduce the tem¬ 
perature of the oil after it has 
been used and returned to the 
oil-supply reservoir and before it has been used a second time. The 
oil pump on the end of the camshaft is marked D. 

In Fig. 223, the oil pump is a simple plunger operated by a cam 


Fig. 221. Typical Plunger Pump 

Courtesy of Reo Motor Car Company, 
Lansing, Michigan 











































































































V 


* 

GASOLINE AUTOMOBILES 315 




Fig. 222. Section and End Elevation of Scripps-Booth Eight, Showing Oiling System 
Courtesy of Scripps-Booth Corporation, Detroit, Michigan 

















































































































































































































































316 


GASOLINE AUTOMOBILES 



Fig. 223. Side and End Sections of Engine with Horizontal Plunger Type of Oil Pump 




































































































































































































GASOLINE AUTOMOBILES 


31? 



on the camshaft. It projects out at right angles on the side between 
cylinders 2 and 3. It is possible to arrange a system of this kind so 
that an extra cam is not needed, one of the regular valve cams doing 
the work of pumping the oil. This makes a simple and inexpensive 
arrangement. The oil suction pipe is marked B and the pipe carry¬ 
ing the supply to the bearings is marked C. Attention is called to the 
connecting-rod oil scoops D, the feed adjustment E, the pressure- 
relief valve F, and to the main oil lead G. 

Individual Pump Pressure Feeding. The expedient of feeding 
the oil by individual pumps, independently driven and capable of 
individual adjustment which enables them to feed any desired amount 
of oil to any par¬ 
ticular bearing re- 
gardless of the 
amount that may 
be fed to any other 
bearing, has been 
widely applied. In 
such a system, if 
obstruction of any 
one of the leads 
should occur, it is 
almost certain to be 
forced out by the 
action of the pump, 
which, in all lubri¬ 
cating systems of established type, is made capable of working against 

enormous pressure. 

One of these lubricators, made for eight feeds, is shown in Fig. 
224. By extending the casing and the longitudinal shaft inside and 
adding more pumps, this type is capable of extension to any desired 
number. - The eight-feed form shown allows of one lead to each of the 


Fig. 224 


Detroit Eight-Feed Multiple Oiler as Used for Motor 
Lubrication 

Courtesy o, Detroit Lubricator Company, Detroit. Michigan 


three main bearings of a four-cylinder engine, one each to the four 


cylinder walls, with a lead remaining for the gear case at the front 
of the motor. 

Gravity Feeding. Feeding of oil by gravity to one or more bear¬ 
ings is a method that has been employed w ith some success, but it is 
now encountered only in rare instances in automobile powei plants. 





318 


GASOLINE AUTOMOBILES 


Splash Lubrication. The feeding of oil to bearing surfaces by 
the simple expedient of enclosing a quantity of it in a reservoir in 
which the working parts are also contained is a successful and widely 
used scheme in automobile motor construction. 

In the splash lubrication system, as will be shown in detail later, 
the lower ends of the connecting rods “splash” up the oil which is in 
the bottom of the crankcase in the form of a huge puddle. Since this 
method, formerly almost universal, has been criticised as wasteful of 
oil as well as productive of much needless smoke, it has been modified 



Fig. 225. Typical Screw 
Type Grease Cup with 
Wing Handle 

Courtesy of Lunken- 
heimer Company, 
Cincinnati, Ohio 





Fig. 226. Lunkenheimer 
Grease Cup with Re¬ 
movable Barrel 



Fig. 227. Lunkenheimer 
Grease Cup with Spring 
Cover for Quick Filling 


by the majority of makers so that the scoops on the ends of the con¬ 
necting rods dip into small narrow troughs provided for this purpose. 
Another objection to this system is that at high speeds too little oil 
is thrown around the interior of the cylinders and crankcase, since 
the initial rotation of the rods has churned or beaten the entire 
supply into a mist, while at low speeds too much is thrown around 
for the work the engine is doing. 

The latter objection has been overcome in the newer engines b\ 
making the troughs into which the connecting-rod scoops dip mov¬ 
able and attached to the throttle lever, so that when the latter is 
opened wide to develop maximum power, the troughs are brought up 
higher, allowing the scoops to dip down deeper and thus supply a 
greater amount of lubricant. 

External Lubrication. In the lubrication of the external parts 
of the motor, such as the pump shaft, magneto shaft, oiler shaft, fan 











































































GASOLINE AUTOMOBILES 


319 


shaft, generator shaft, air pump shaft, etc., an entirely different 
method of lubrication is necessary—one that is more simple in every 
respect, allows the use of more simple lubricating devices, and does 
not require anything like the care and adjustment previously pointed 
out for the internal parts. 

Oil and Grease C ups. Chief among the devices used for lubricat¬ 
ing these outside parts are oil and grease cups, the oil cups being used 
in decreasing quantities and the grease cups in increasing quantities. 
Formerly, oil cups were much used, but they gave poor satisfaction, 
collected dirt, and were unsatisfactory generally. In the use of 
grease cups, there are but three things to observe: They should be 
large enough, accessible, and easy to fill. 

For application to spring eye-bolts there is a particular type 
of grease cup. This grease cup is of the type that feeds by being 
occasionally screwed up a small distance as the bearing uses up the 
lubricant, and its positive action is rendered more certain by the use 
of a detent (not illustrated) that holds the cover in any position in 
which it may be left. The grease is contained in the entire cap which, 
when unscrewed from the lower portion, is readily and conveniently 
filled by scooping up the grease. 

A form quite generally used is the simple cup shown in Fig. 225. 
This is a screw-compression cup from which the lubricant is forced out 
by screwing down on the reservoir. This form is prevented from com¬ 
ing loose by the compression spring, here shown very much compressed 
below the ratchet, which governs the screwing down of the reservoir. 
To fill the reservoir, the ratchet portion is held down and the top 
screwed off, turning in the reverse of the usual direction. Although 
the top is fitted with a wing handle, it can hardly be considered easy 
to refill. 

Another widely used form is seen in section in Fig. 226. This has 
a larger handle and, in this respect, may be considered easier to fill. 
A type which is rapidly coming into use and has all the advantages of 
the other two, and more, is shown in Fig. 227. This is a plain 
screw type with a large handle, but the cap is of sheet brass and 
is sprung into place. As this is sprung off by the plunger inside 
when screwed away out, filling is reduced to a matter of sec¬ 
onds. The plunger screws all the way in and affords pressure all 
the way. 


320 


GASOLINE AUTOMOBILES 



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GASOLINE AUTOMOBILES 


321 


The simplest form of oil cup has a hole in one side, which is 
covered with a spring-held cover. To use it, the cover is lifted with 
the fingers until the hole is uncovered, then the point of the oil can 
is inserted and the oil forced in. 

GENERAL LUBRICATION 

Lubricating the Whole Car. It is best for both the private owner 
and the repair man to have a definite regular system for going over 
the grease and oil cups on the chassis. As shown in Fig. 228, there 
are a number of cups varying from 30 to 32 and upward, as well as 
oil holes, which need to be looked after occasionally. The worker 
should get an oiling chart and fix firmly in his mind the requirements 
of the .various parts to be oiled or greased and should regulate his oil 
and grease cups by hand from day to day and week to week so as to 
produce the desired results. 

Lubrication of Other Parts. The precise lubrication of the 
clutch, transmission, rear axle, and other more important units will 
be found discussed in detail under their respective headings. 

There are signs at present that the lubrication of the motor may 
be controlled through the medium of a thermostat in order to conserve 
every unit of heat needed in the vaporization of the fuel and thus 
increase the efficiency of the engine as a whole. There would be a 
double advantage in this, for lubrication would be placed on a more 
economical basis. In using the thermostat, smoking and carboniza¬ 
tion would be reduced, and their heat utilized. This process, carried out 
to a logical conclusion, might result in forced lubrication of all points 
on the chassis by means of the oil-pump system. A system of forced 
lubrication somewhat like the above has been produced in the Fergus 
car, but here the idea was to reduce the amount of work in connection 
'with lubrication. The number of points outside of the automatic 
oiling system, which required oil or grease application by hand, has 
been reduced in this car from 80 to 11. Some 18 points in the spring¬ 
ing system have been eliminated entirely by enclosing the springs in 
leather boots, grooving and drilling them, and forcing oil in under 
pressure from the main pump. It is questionable, however, whether 
the results as obtained in this case are worth the cost in money 
and complication, for this system gives a freak appearance to 
the car. 


322 


GASOLINE AUTOMOBILES 


Oils and Greases 

Characteristics of Good Oils. The variety of oils and greases 
recommended for automobile use is so extensive, and there are so 
many cheap and worthless lubricating compounds on the market, 
that it is almost impossible for the purchaser without technical knowl¬ 
edge to discriminate between them. The various tests from time to 
time recommended, whereby the user may ascertain for himself the 
quality of the lubricant he is using, are rarely of positive value, since 
the compounders of the shoddy oils and greases are usually sufficiently 
expert chemists to concoct admixtures that will successfully pass 
such simple tests as are available to the average layman, and will fail 
only under the more critical analysis of a competent chemist, or under 
the severe and more risky practical demonstration that results from 
long use, in the course of which the worthlessness of the lubricant is 
likely to be found out only at the cost of serious injury to the 
mechanism. The consequence is that the only really safe policy to 
follow is the purchase of the highest grades of oils and greases, 
marketed by concerns of established reputation. 

The oils generally found best for gasoline-engine cylinder lubri¬ 
cation are the mineral oils derived from petroleum, though castor 
oil is found to possess peculiar merits for the lubrication of air-cooled 
motors working at high temperatures in which the friction of steel 
surfaces working over steel surfaces is often involved. This oil is 
exclusively employed in aviation motors, such as the Gnome, which is 
built with steel cylinders and pistons, and it is often utilized in 
racing automobile motors. Its chief merit seems to be that instead 
of withstanding the high temperatures, which is the result sought in 
the use of mineral oils of high fire test, it burns up clean without 
leaving any deposit upon the cylinder walls. It has to be fed in 
excessive quantities, which makes its use a rather expensive method of* 
lubrication. But for the peculiar services for which it is adapted, it 
certainly proves most satisfactory. 

In greases and oils used for the lubrication of parts not exposed 
to such high temperatures as prevail in gasoline-engine cylinders, the 
admixture of vegetable and animal greases and oils with mineral oils and 
greases is not objectionable and often may be of considerable benefit. 

Graphite is a solid lubricant and is very advantageous to 
employ in many parts of an automobile. In the deflocculated form, 


GASOLINE AUTOMOBILES 


QOO 
0^0 

admixed in very small percentages with cylinder oils, gearbox greases, 
etc., there is no question but what it greatly conduces to smooth 
running and to long life of bearings. Its resistance to the very 
highest temperatures makes it constitute a considerable safeguard 
against immediate injury in case of neglect to replenish the lubri¬ 
cants as often as is properly required. 

Testing Oils for Acid, Etc. Oils must be purchased with much 
care. Once an oil is found which does the work satisfactorily, it 
should be adhered to consistently. No two oils are exactly alike, and 
for that reason, no two will do the same work under the same condi¬ 
tions in the same way. So, it is advisable to experiment only until 
an oil is found which will do the work. Thereafter, stick to that 
brand. As an instance of the impurities which may be found in oils, 
acids may be mentioned. These are fatal to delicate and closely 
machined parts, such as ball bearings, cylinder walls, pistons, etc., and 
consequently they should be watched for. 

Pure mineral oils contain little acid, and what they do contain 
is readily determined. Vegetable and animal oils, on the other hand, 
all have acid content and under the action of heat this may be lib¬ 
erated. A simple home test may be practiced as follows: Secure from 
a druggist a solution of sodium carbonate in an equal weight of water. 
Place this in a small glass bottle or vial. To test an oil, take a small 
quantity of the lubricant and an equal amount of the sodium solu¬ 
tion. Put both in another bottle, agitate thoroughly, and then allow 
it to stand. If any acid is present, a precipitate will settle to the 
bottom, the amount of the precipitation being a measure of the 
amount of acid present. 

Another method is to allow the acid, if there is any, to attack 
some metal. To do this proceed as follows: Soak a piece of cloth or, 
preferably, wicking in the oil suspected of containing acid. Select a 
piece of steel at random and polish it to a bright surface. Wrap the 
steel in the soaked rag or wicking, and place in the sunlight but 
protect it from wind or weather. Allow it to stand several days, and if 
there is no sign of etching of the surface, repeat with a freshly soaked 
rag, being careful to use the same oil as before. After two trials, 
if no sign of the etching appears, you may consider it free from acid. 

Principles of Effective Lubrication. To render lubrication 
positive and effective there are certain conditions regarding the 


324 


GASOLINE AUTOMOBILES 


design of bearings and the feeding of lubricants that must be scru¬ 
pulously observed. 

The proper application of a lubricant to a revolving shaft 
passing through a bearing requires that definite space be provided 
. between shaft and bearing for the lubricating material. The amount 
of this space varies with the size of the shaft, the speed of rotation, 
and other conditions, but in a general way it can be specified that 
the space must be greater as the shaft diameter increases, and greater 
for heavy oils and low speeds than for light oils and high speeds. 
For the crankshafts of automobile engines, to take a specific example, 
it is rarely desirable to have the bearing smaller than from .0005 
to .0015 inch larger than the shaft. The annular space thus pro¬ 
vided, as suggested at A in the end and sectional views in Fig. 229, is 
occupied by the lubricant, which, contrary to another general impres¬ 
sion, will not be squeezed out unless the shaft is loaded above its 




Fig. 229. Condition of Bearing for Proper Lubrication 

capacity; this is more likely to occur because the bearing area is too 
small than from any other condition likely to be encountered. 

With the bearing area large enough—which means that the 
specific pressure on its projected area must not be excessive—the 
tendency of the oil to remain in its place by capillary attraction, 
perhaps helped by the pressure under which it is fed into the bearing, 
is much greater than the tendency of the load upon the shaft to force 
it out. 

From the foregoing, it is evident that the condition of effective 
lubrication is that in which the shaft literally floats in an oil film of 
microscopic thickness, this film completely surrounding it and so 
protecting it from any contact whatever, under normal conditions, 
with the bearing surface. The necessity for the accurate fitting of 
bearings is not to secure a close metal-to-metal contact, as is some- 






























GASOLINE AUTOMOBILES 


325 


times erroneously supposed, but to provide an oil film of the necessary 
uniform, instead of an irregular, thickness. 

LUBRICATION TROUBLES AND REMEDIES 

Care of Lubricant in Cold W eather. Nearly everyone realizes 
the amount of care necessary with cooling water in freezing weather, 
but few realize that extreme cold has practically the same effect upon 
lubricants. In the coldest weather, a lighter grade of oil specially 
made to withstand low tempera¬ 
tures should be used. If a 
special oil cannot be obtained, 
the lighter thinner quality will 
suffice, as even when thickened 
up by the low temperatures this 
oil will flow more readily than 
the thick oils. Sometimes the 
slow circulation of the oil in cold 
weather allows the motor bear¬ 
ings to run dry and heat. This 
trouble can be remedied by 
changing to a lighter oil. The 
same is true of the clutch oil 
which is in the multiple disc 
running in oil. Thick oil in this 
in cold weather will often thicken 

up and stick SO the clutch will Fig. 230. Mammoth Grease Gun for Garage Use 
, ., Courtesy of “ Motor World” 

not work well. 

Mammoth Grease Gun. For the average shop which handles a 
good many cars a day, too much time is wasted in using an ordinary 
method of filling a transmission, rear axle, or other large part, with 
grease. A mammoth grease gun can be constructed to do this same 
work in a few seconds. A form operated by compressed air is shown 
in Fig. 230. It consists of a steel cylinder about 8 inches in diameter 
and perhaps 7 feet long mounted vertically on a platform which is set 
on castors so that it can be wheeled around the shop as needed. A free 
piston is placed in the cylinder, above the grease, and air admitted 
through the central opening in the screw top by screwing on a com¬ 
pressed air hose. The outlet hose at the bottom is made long 































320 


GASOLINE AUTOMOBILES 


V 


enough to reach any ordinary point on the average car. When a 
transmission is to be filled, the platform is wheeled up to the car, 
the bottom hose put in the transmission, and the cock opened. Then 
the air hose is connected and the pressure turned on; the grease will be 
forced out in a hurry, filling the case in a few minutes regardless of 
the quantity needed. A somewhat similar device can be made in a 
smaller size. This device is almost an exact copy of the ordinary hand 

grease gun, but it has a rod, threaded 
through the cap, which operates the 
plunger. One man can hold the gun while 
another turns the handle, which forces 
out a tremendous quantity of grease in a 
short time. 

Oil Tank and Outfit for Testing 
Bearings. A tank for testing the leakage 
of bearings, particularly engine bearings 
that are loose, may be constructed by 
fixing in the top of a small tank a gage 
which will read up as high as 20 pounds, 
an inner-tube valve stem for sup¬ 
plying and holding air pressure, and a 
filling cap which is air tight; at the bot¬ 
tom of the tank an outlet is placed which 
is controlled by a valve or cock. This 
outfit, as shown in Fig 231, is partially 
filled with oil. Air is then pumped in, 
and the connection is made into the 
oiling system after the removal of the 
oil pump. The gage will indicate the 
pressure at which the oil is being pumped 
through, and the leakage of the oil around the bearings will show their 
looseness. Close-fitting bearings do not leak. 

Getting Oil Barrels Out of Sight. The oil barrels around the 
garage are in the way; they collect dirt and spread oil into everything 
within reach and take up much valuable space. A good way 
to get rid of them is to build a rack close to the ceiling, as shown 
in Fig. 232, and put them up there. A pipe with a faucet at its lower 
end for drawing oil leads down from each barrel; these pipes are 



Fig. 231 


Pressure Outfit for Testing 
Loose Bearings 

Courtesy of “Motor World” 






























































































GASOLINE AUTOMOBILES 


327 



Fig. 232. 


Method of Elevating Oil Barrels to Save Space 
Courtesy of “ Motor World ” 


grouped over a small pan which catches the drip. Filling these 
barrels is easier than it seems. Simply connect a pipe from the 
barrel of new oil to the 
overhead barrel to be 
filled, apply the air pres¬ 
sure carefully at the 
bung, and the oil will 
be forced up. 

A more simple 
method of covering and 
protecting the barrels is 
to have a box, or stand, 
large enough for three or 
more barrels, made from 
light lumber. Then bore 
a small hole, at the place 
where each barrel will 
stand, for the faucet, as 
Fig. 233 shows. Generally, three barrels will be sufficient, as one 
for heavy oil, one for light oil, and one for kerosene will cover all 
ordinary work. The shelf 
which holds the various 
measures should be at¬ 
tached to the frame. 

A convenient oil- 
drain rack in the form of 
a small square box, say 
6 to 8 inches deep, can be 
made with tin. Punch a 
series of small and me¬ 
dium size holes in the top 
of the box. When the 
funnel has been used for 
filling an oil tank or meas¬ 
ure, it can be placed in the 
rack and allowed to drain. In this way, oil waste is minimized and 
the place is kept free from oil drippings, which soon gather dust and 
then are tracked into office and customers cars. 




















































328 


GASOLINE AUTOMOBILES 


Oil Settling Tanks. If lubricating systems are drained as often 
as both manufacturers and oil people recommend, there is a good deal 

of oil around, which is heavy and of a doubt¬ 
ful quality. But if this oil can be allowed 
to stand, or can be filtered, a large quantity 
of it can be used for other purposes. If a 
tank of fairly large size is made with a series 
of faucets or cocks at different levels, some¬ 
what like that shown in Fig. 234, enough of 
the oil can be saved to resell at a good profit, 
or, if there is no idea of selling it, it can be 
used for other machinery or for other pur¬ 
poses, where the need for high-quality oil is 
not so great. The oil drawn off the crank¬ 
case is poured in at the top and gradually 
settles, the heavier sediment going to the 
bottom, the thickest oils next, and so on, 
until the top will show a fair quality of light oil, and the layer next 
to it a fair quality of medium oil, and so on down to the bottom. 

Oil Filtering Outfit. 



Fig. 234. Settling Tank with 
Cocks at Various Levels 
for Saving Oil 



If one has the apparatus, 
filtering is much superior. 
A simple filtering outfit is 
shown in Fig. 235; this 
consists of the tank with 
provision around the inside 
for supporting a fine brass 
screen and two or more 
funnels, one above the 
other. The mouth of each 
of the funnels is filled with 
cotton waste, and the fun¬ 
nel set in place, then the 
next one is filled and set 
above it, and finally, the 

Fig. 235. Filter of Simple Construction for Filtering Oil } 3rass gauze is laid aCl’OSS 

at the top. As the oil is drawn off, it is poured in at the top. The 
wire catches any large particles, while the oil in filtering through the 






































































































































































GASOLINE AUTOMOBILES 


329 


The Tubing is Easily 
Threaded off 


two or three bunches of waste will lose practically all its impurities, 
coming out perfectly clear. After each use, the waste is removed 
and burned, and new waste put in its place. 

Oil measures, funnels, and other containers should always be kept 
clean. The oil left on them soon collects dust and dirt, and the next 
time some of this old oil will be poured into the engine with the fresh 
oil. All oils do not mix, and chemical action may be set up 
between old oil of one quality on the can and new oil of another 
quality in the can. Kerosene or a little gasoline should be poured 
in the containers or funnels to clean them off. This liquid 
should be rinsed out of the cans and put into a settling or filtering 
tank and practically all of 
it recovered. 

Bending Oil Pipes. 

Frequently an oil pipe 
which has a curve or spiral 
in it, or even a series of 
coils has to be replaced. 

If bent by hand, a kink 
may be made in the pipe 
which will lead to a future 
break. A simple fitting 
for bending these pipes can be made in a few minutes. Take a piece 
of hard wood about 3 inches square and 9 inches long and turn it 
up round in the lathe, then down one end, as shown in Fig. 236, and 
cut the spiral grooves or threads in it. These should be about ye 
inch in width and cut with a round-nosed tool so as to get a smooth 
bottom to the grooves. When a pipe is to be bent, fill it with resin, 
a fine lead rod, or anything flexible. The wood can be held in the side 
of the vise and the tubing wound onto the threaded end. If the 
pipe is of a heavy gage, anneal it by heating and plunge it into cold 
water before starting to bend it. After bending, melt out the filler. 



Fig. 236. Hard Wood Fixture for Bending Oil Pipe 


Summary of Troubles with Lubrication Systems 

Crankcase Oil. This should be changed about every 500 miles as, 
by this time, the lubricating qualities of the oil are nearly exhausted. 
After draining the oil, wash out the crankcase with kerosene and 
see that the kerosene is removed before putting in fresh oil. 



































































330 


GASOLINE AUTOMOBILES 


Grease Cups. These are usually located on the rear axle, steer¬ 
ing knuckles, steering-column base, and many other parts. They 
should be kept constantly filled with cup grease. These grease cups 
should not be confused with small oil holes having caps which can be 
raised but not unscrewed. Grease cups should be screwed down 
occasionally in order to force the grease down to the bearing surface. 

Neglect of Lubrication. Neglect of lubrication is responsible 
for many troubles. Any automobile requires careful attention to its 
lubricating system. The owner will find it to his advantage financially 
to see that all necessary parts are properly lubricated. 

Steering Gear. The steering-gear parts require occasional lubri¬ 
cation. These parts include steering rod; worm, or sector, and gear; 
steering link at both ends; foot-pedal pivot or bearing; and all joints. 

Too Much Oil in Crankcase. Usually drain cocks are provided 
in the crankcase and are so located that when they are opened 
they will drain off only the surplus oil. 

Troubles with Mechanical Lubricator. If one of the sight feeds 
fills with oil, it indicates too rapid feeding of oil. Shut off the valve 
on the top of the lubricator till the glass is clear. If it does not 
clear up shortly, the probability is that it is necessary to clean the 
lubricator. 

Mixing Gas=Engine Cylinder Oil with Fuel. This is advocated 
by the makers of a few two-cycle engines, the proportion being one- 
half pint of best gas-engine cylinder oil with every five gallons of 
gasoline. This, however, is not considered good practice. 

BEARINGS 

Types of Bearings Required for Different Locations. As the 

portion of a mechanism upon which, more than upon any other 
element, its continued operation and long working life depends, the 
bearings of any piece of machinery should be of the most approved 
design and most perfect construction. The crankshaft and connecting- 
rod bearings, which are the most important on the motor, are of 
the plain type on the majority of engines. Of the 1914 cars but six 
different makes had ball bearings for the motors, and, of these, two 
used plain bearings on some models, so that only four makers actually 
believed in ball bearings for engine shafts. For camshafts there is 
more difference of opinion, while on fan shafts almost all makers use 


GASOLINE AUTOMOBILES 


331 


ball bearings. The other shafts, as pump, oiler, magneto, air-pump, 
generator, etc., are generally of the plain, solid, round type. 

Engine bearings, however, are generally of the split, or halved, 
type, the upper and lower halves being practically duplicates. A 
reason for this construction appears as soon as one considers the 
application of the bearings to the shaft. It is granted that a crank¬ 
shaft must be as firm and solid as possible, and hence it must be made 
in one piece. As ball bearings also are made in one piece, there arises 
at once the difficulty of getting the bearings into place on the one- 
piece shaft. This difficulty has necessitated cutting the shaft or else 
making it especially large and heavy in those cases where balls are 
used. With the split type of bearing there are no troubles of this kind 
and the bearings are adjustable for the inevitable wear. 

Plain Bearings. The conditions that determine the proper 
proportioning and fitting of plain bearings have already been referred 
to in a preceding paragraph. 

The materials of plain bearings are commonly varied to meet 
different conditions. With liberal bearing areas, in situations where 
it is desired to bring about a perfect fit with the minimum amount 
of labor, and to protect the shaft from wear in case there is failure of 
the lubrication, the various types of babbitt metal—which usually 
are alloys of tin and lead, with sometimes some admixture of antimony 
and other alloys—are widely regarded as the most serviceable. Prob¬ 
ably the greatest advantage of a babbitted bearing is that, if the 
lubrication should fail, the low melting point and the soft material of 
the bearing will insure its fusing out without injury to the more 
expensive and valuable shaft. 

Brass and bronze bearings, particularly the phosphor bronzes 
and the bronzes in which the proportion of tin is high and that of 
copper low, with sometimes the admixture of a proportion of zinc 
or nickel, will allow the use of materially higher pressures per square 
inch than can be safely permitted on babbitted bearings. 

Steel shafts in cast-iron bushings, and even in hardened-steel 
bushings, make much better bearings than one might think, and 
though immediate trouble is to be anticipated with such a bearing 
should its lubrication fail, even momentarily, this trouble is more or 
less true of any bearing that can be devised. Since steel-to-steel and 
steel-to-cast-iron permit much the highest loadings per unit of area 


332 


GASOLINE AUTOMOBILES 


that are permissible with any type of metal-to-metal bearing, the 
merits of these materials are perhaps less appreciated than might be 
desirable. Steel pins through steel bushings, however, are not an 
uncommon construction for the piston-pin bearings in high-grade 
engines. 

One noticeable feature of plain bronze or other plain bearings 
for automobile use is that they are always grooved for oil circulation. 
This is done by easing off the edges, then cutting a spiral groove by 
hand diagonally across to the other edge or to the center point where a 
similar groove from the other side is met. In a solid bearing, the 
groove is generally cut both ways from a centrally drilled oil hole, 
while in split bearings the grooves in each half usually form a modified 
letter x when viewed in plan, that is, two grooves start spirally inward 
from each edge near the ends, and all four meet in the center. This 
central point may be the spot where the oil enters or where it leaves. 
These grooves are seldom of very great depth, perhaps .008 to .010 
(eight to ten thousandths). 

New Oilless Bearings. A form of bearing that is new to the 
automobile but old in years is now coming into use. This is made of 
special wood which previously has been impregnated with oil. By 
saturating the pores of the wood with oil in this way, it is claimed that 
no lubricant need be used on the bearing for years. They are turned 
1 and fitted the same as bronze or other bushings. 

Another oilless bearing is made of bronze with graphite inserts; 
this bearing is sufficiently soft to form the lubricant, yet sufficiently 
hard to retain its form and shape. Approximately one-half of the 
inner surface of the bearing is graphite, the two alternating in various 
ways, that is, the graphite is put in in spirals, in circles, in double 
diagonals, in a herringbone pattern, in zigzags, and otherwise. 

Roller Bearings. Roller bearings, constituted by the inter¬ 
position of a number of small rollers between shafts and casings, 
are a type of bearing widely employed in automobiles. 

A much-favored construction is the tapered roller bearing 
illustrated in Fig. 237. This stands up very well under both thrust 
and radial loads. 

Another type of roller bearing is that illustrated in Fig. 238, 
which is the type used on the Ford rear axle. This is one in which 
the rollers are small flexible coils made of strip steel, finally hardened 


GASOLINE AUTOMOBILES 


333 




and ground accurately to size. This type of roller can be depended 
upon to work without breakage or injury even though there be con- 


Fig. 238. Hyatt Flexible Roller Bearing Partly Disassembled to Show Components 
Courtesy of Hyatt Roller Bearing Company, Newark, New Jersey 

It will be noted in Fig. 238 that there is a solid steel shell to go on 
the shaft and fit it tightly, and another to fit into the case or support, 
whatever it may be, perhaps attached there permanently. Between 


Fig. 237. Timken Roller Bearing 
Courtesy of Timken Roller Bearing Axle Company 


siderable deflection or inaccuracy in the alignment of shaft or casings, 
the flexibility of the individual rollers taking care of such small errors. 









334 


GASOLINE AUTOMOBILES 


these two comes the cage carrying the flexible rollers. Any load 
imposed upon the shaft is transmitted to the inner sleeve and by 
it to the flexible rollers; these rollers absorb the load so that none of it 
reaches the outer case. Furthermore, shocks coming to the case 
from without are absorbed by the flexibility of the rollers and, vice 
versa, shocks to the shaft do not reach the case. 

Ball Bearings. Probably the best of all bearings, except for 
certain special applications in which it is difficult to utilize them in 
sufficiently large sizes to assure durability, are the annular ball 
bearings of the general type illustrated in Figs. 239 to 243, inclusive. 
The basic feature of the most successful of modern annular ball 

bearings is their non-adjustability, the 
balls being ground very accurately to 
size and closely fitted between the 
inner and outer races so as to allow 
practically no play. 

The reason that the best ball bear¬ 
ings are not made adjustable is that in 
any conceivable type of ball bearing 
one or the other of the races rotates 
and the other remains in a fixed posi- 

Fig. 239. Annular Ball Bearing tion The resu l t fe t h at there must be 

a loaded side to the race that does not rotate, with the consequence 
that when wear occurs, it wears the ball track deeper at this point 
than on the unloaded side. With the bearings thus worn, it is almost 
impossible to make an adjustment, for the attempt can result only in 

tight and loose positions as the balls come 
out and in of the spot that is more deeply 
worn. 

This condition has led the designers 
and manufacturers of the various types of 
high-grade annular ball bearings that are now on the market to dis¬ 
card adjustment as of no value and to substitute in its place quali¬ 
ties of material and hardness of surface which, in combination with 
the provision of sufficient sizes, are found to reduce wear to so small 
an amount that it is almost inappreciable. A bearing thus made 
can be therefore depended upon to outlive almost any other part of 
the mechanism in which it is placed. 




i i 



Fig. 240. Section of Annular 
Ball Bearing 







































GASOLINE AUTOMOBILES 


335 


The carrying capacities of ball bearings, as compared with those 
of roller bearings, are much greater than a casual consideration might 
lead one to suppose, TL heoretically, the contact of a roller bearing— 
between a roller and one of the races—is a line contact, while that 
between a ball and a ball race is a point. But, practically, since some 
deformation occurs in even the hardest materials under sufficient 
load, the line contact in the roller bearing becomes a rectangle and the 
point contact in the ball bearing becomes a circle. Now the vital 
fact is that the area of the rectangle in the one case is substantially 
equal to that of the circle in the other—with given quality of materials 
and a given loading. So a ball bearing is fully as capable of carrying 
high loads as a roller bearing; besides, it avoids the risk of breakage 

il 


Fig. 241. Ball Cage of Annular Ball Bearing 

that usually exists with rollers because of the impossibility of making 
them perfectly true and cylindrical. 

To assemble ball bearings of the type illustrated in Fig. 240, either 
of two expedients may be adopted. One is to notch one or both of 
the ball races, so that by slightly springing them a full circle of balls 
can be introduced through the notch. The other scheme is to employ 
only enough balls to fill half of the space between the races, which 
permits them to be introduced without any forcing, after which they 
are simply spaced out at equal intervals and thus held by some sort 
of cage, or retainer, such as is illustrated in Fig. 241. 

Ball bearings of the common annular type are quite serviceable 
to sustain end thrust as well as radial loads. For the best results 
under such loads, however, it is essential that the load be distributed 
equally around the entire circle of balls, for which reason the system 






336 


GASOLINE AUTOMOBILES 


illustrated in Fig. 242 is a means of avoiding the unequal distribution 
of pressure likely to result from the slightest inaccuracy of fitting. In 



Fig. 242. Bearing Designed 
to Equalize Loads 



Fig. 243. Annular Ball Bearing Mounted for 
Thrust Loads 



this construction the outer ball race, shown at A, is provided with 
a spherical outer surface, permitting it to rock slightly in the mount¬ 
ing C, into the position shown in an exaggerated degree at B. It 
thus floats automatically to a position at exact right angles to the 

shaft upon which it is mounted, 
and so insures even loading of 
the whole ball circle. 

An annular ball bearing 
designed for thrust loads alone 
is illustrated in Fig. 243. In 
this bearing, the lower race A is 
provided with a spherical face, 
described from the radius B, so 
that, as in the case of the bear¬ 
ing illustrated in Fig. 242, when 
in use it automatically floats 
under the load into such a 
position that all the balls are 
under equal pressure. 

To secure uniformly satis¬ 
factory results from ball bear¬ 
ings, it is not only necessary in the first place to have them of the 
best materials, accurately made, and of sufficient sizes, but thereafter 
they must be always protected from dust and grit and from water and 
acids which tend to cause rust. They must also be kept lubricated, 


Fig. 244. Bearing for Combined Radial and 
Thrust Loads 

Courtesy of New Departure Manufacturing 
Company, Bristol, Connecticut 


































GASOLINE AUTOMOBILES 


337 


Combined Radial and Thrust Bearing. The need for a bearing 
which would take ordinary radial loads well and also sustain thrust 
has led to the development of combined radial and thrust bearings, 
one being illustrated in Fig. 244. This is constructed to take either 
form of load equally well, and for this reason has displaced a pair of 
ball bearings in many circumstances where formerly it was thought 
necessary to use a radial ball bearing to sustain the load and a thrust 
ball bearing to absorb the end thrust. In this way it represents an 
important economy. Furthermore, it is economical of space, as it 
takes less room than the former pair of bearings used for the same 
two purposes. 


FLYWHEEL SUB=GROUP 

Importance of Flywheel. With the growing tendency toward 
smoother and more even running and the demand for lower low' 
speeds and higher high speeds, the flywheel, which w r as looked upon 
as a necessary evil for many years, is now receiving more attention. 
The designers realize that the flywheel plays an important part in 
balancing^that if it is too heavy the engine will be slow to pick up 
speed and will not run very fast, and that if it is too light, the engine 
will be very “touchy” and will not withstand quick variations from 
high to low 7 or low to high speed, nor will it throttle dowm very slowly. 

Flywheel Characteristics. Weights. With weights being reduced 
to the limit in order to get higher engine speeds, the flywheel has 
received some paring down. Formerly, designers erred if at all 
on the heavy side wflth flywheels, but when they began changing the 
entire design of the engine to save a few pounds, they did not overlook 
the flywheel. In the flywheel, too, the growing use of counterweights 
has had an influence. 

Sizes. Designers realize, now that the hampering sub-frames are 
out of the w 7 ay, that the larger the diameter the better the flywheel 
effect for equal or less weight. As a result, many flywheels have been 
increased in diameter as they have been reduced in weight. 

Shapes. Flywheel shapes, that is, sections, used to be rec¬ 
tangular or almost square, with a solid w^eb or spokes practically in 
the center. Clutches, starter-ring gears on the outer surface, and 
other contributing causes have changed the character of flywheels 
so that few 7 have the rectangular shape or character now. I lie method 


338 


GASOLINE AUTOMOBILES 


of using fan blades as flywheel spokes has also fallen into disuse; 
although at one time it was widely tried and appeared to be a means 
of eliminating the fan entirely. 

Something of the present shape of flywheels can be seen by refer¬ 
ring back to Figs. 217, 222, and 223. In the first figure, the flywheel 
has a triangular section with a solid web set at an angle so as to bring 
the flywheel nearer the engine; the inner surface is tapered to suit 
the clutch. In Fig. 222, the shape is entirely different and apparently 
much lighter. This is an eight-cylinder engine. Here the flywheel 



Fig. 245. Three Common Methods of Fastening Flywheel: A, Flange and Series of Bolts; 

B, Plain Key; C, Key, Taper and Nut 

Courtesy of N. W. Henley Publishing Company, New York City 


section as a whole has a short U-section, being externally a short 
section of a cylinder. The web, too, is perfectly straight at ofle end. 
The inside is cut out for the clutch, but with a very slight angle. The 
shape of the flywheel in Fig. 223 is somewhat similar to that of Fig. 
217, but it is wider and not so thick. It shows a larger diameter, too. 
The exterior is plain and straight except at the front edge where the 
starting-ring gear teeth are cut into a raised portion of it. The web is 
straight and solid, close to one end, but not flush with it as in Fig. 222. 





















































































































































GASOLINE AUTOMOBILES 


339 


Methods of Fastening Flywheels. That part of the flywheel 
which is most interesting to the repair man is the method of fastening, 
or rather the inverse of this, the method of removal. There are three 
general methods of fastening flywheels to crankshafts, and these are 
shown in Fig. 245. They are the plain round end with a key, as 
shown at B; the tapered end with key, nut, and lock nut, as shown at 
0; and the method of bolting to a circular flange integral with the 
crankshaft, as indicated at .1. The first is widely used for stationarv 
gas and marine engines of very low price, but very little, if at all, on 
automobile engines. The second has been used, but is rapidly going 
out, as it is, like the first, a low-priced method which did not prove 
satisfactory. The third method is rapidly becoming universal. 

In use, the flywheel flange on the crankshaft is generally five 
or six inches or a figure between these, in diameter, with six to ten 
bolts. In the form shown at C, Fig. 245, the flange is exterior to the 
flywheel, but in Figs. 217 and 223, the more general method of grooving 
the flywheel hub to receive the flange will be noted. In Fig. 245, 
the bolt shown has a countersunk head let into the flywheel surface-; 
in general, the bolt head is either standard or else round and set into a 
countersink. In this case, it is slotted for a screwdriver. Also a 
single nut is shown, whereas a nut and lock nut, or, at least, nut and 
lock washer, are always used. 

Flywheel Markings. As has been noted previously under 
Valves and Valve Timing, the surface or rim of the flywheel generally 
carries upon it marks to indicate to the repair man the timing of the 
motor. Some makers give only one or two marks for a single cylinder, 
reasoning, with some degree of correctness, that if the first cylinder 
is set right, the others must be pretty nearly so, and that more marks 
would only confuse. Others put on their flywheel all the marks for 
all the cvlinders. 

Summary of Engine=Group Treatment. In Parts I, II, and III, 

the entire engine group has been discussed in detail. The different 
sections have been handled according to present practice and methods 
of operation. It is easily possible that the near future may bring 
about the elimination of one or more of these groups or its combina¬ 
tion with some other. 

The engine, too, has been discussed in its present form only, 
although some attempts have been made here and there to indicate 


340 


GASOLINE AUTOMOBILES 


the trend of developments. He would be a very foolish man who, 
knowing the past history of the automobile engine, would say that it 
has now reached perfection and will always have its present form. 
On the contrary, there seems every reason to believe that hardly a 
single feature of our present-day engine, at least in its present form, 
will be found in the up-to-date engine of ten or twenty years from 
now. This constant change renders a work of this kind almost 
impossible of absolute up-to-dateness, for changes are actually made 
and put into use while the book is being printed. As far as possible, 
however, the work aims to discuss the modern developments and yet 
to give the repair man, in particular, the information he needs as he 
comes in contact with cars of all classes, ages, and conditions. 

SUMMARY OF INSTRUCTIONS 
VALVE SUB=GROUP 
Valves 

Q. For what purposes are valves used? 

A. Valves are used (1) to admit the mixture created in the 
carburetor into the cylinders at the proper time in the stroke and in 
the proper quantity (called admission or inlet valves); and (2) to allow 
the burned gases to be exhausted from the cylinders at the proper 
time in the cycle (called exhaust valves). At all other times the valves 
remain tightly closed. The valves, closing upon a machined seat 
and opening and closing at precise times and in an exact manner, give a 
control over the operation of the engine which is not possible in any 
other way. 

Q. How are these valves opened and closed? 

A. By means of cams, or projections, upon a rotating shaft 
called the camshaft, these projections raising the valve off its seat, or 
opening it, at the proper time. When the projection allows the 
valve to come down onto its seat, or close, a strong spring comes into 
action, forcing it to do this in a positive manner. 

Q. How is the camshaft operated? 

A. By gears or chains from the crankshaft, these being designed 
and assembled carefully, so that the camshaft will revolve at precisely 
half the speed of the crankshaft. 

Q. Why should the camshaft revolve at half the crankshaft 
speed? 



GASOLINE AUTOMOBILES 


341 


A. Because the operation of opening and closing the valves 
comes on every other stroke only, and the camshaft really works 
twice as slowly as the crankshaft. 

Q. What is the general form of a valve? 

A. The usual form is called a poppet valve, and its section is 
that of a letter T, having a long slender stem at the top of which is a 
large flat head. The lower surface of this head is machined off to 
fit the seat in the cylinder, while the upper surface is rounded up to 
the center, where a slot for a screwdriver is provided. 

Q. Are there other forms of valves? 

A. The piston form of valve is little used, but the sliding-sleeve 
valve is used on all Knight type of engines and some others. In addi¬ 
tion, a few motors have been built with rotating-disc valves. The 
piston valve is similar to the usual piston, having a reciprocating 
motion in a special round-valve chamber made for this purpose. In its 
movements up and down, it uncovers ports in the walls, thus giving 
the equivalent of the poppet-valve opening. The sliding sleeve is a 
hollow cylindrical member entirely surrounding the piston and recip¬ 
rocating in the same manner. In its up-and-down motions, ports in it 
register with ports in the cylinder walls at the proper points in the 
cycle, thus corresponding to the opening of the poppet valve. The 
rotating-disc valve acts on the same plan but consists of a flat or 

a conical disc which is gear-driven from the crankshaft. It has a hole, 

% 

or port, in it which registers with other ports in the cylinder at the 
correct time in the cycle. There are other forms of valve but none 
in wide use. 

Q. What are the advantages of the poppet valve? 

A. Its simplicity is its greatest asset. The poppet valve is 
the simplest and most easily understood form of all. In addition, it 
will withstand continuous operation at the highest temperatures. 

Q. What are its disadvantages? 

A. It affords a comparatively small opening, smallest at the 
beginning and ending of the suction stroke, where it should be largest; 
it has a noisy hammering action which makes for rapid wear, constant 
adjustment, and frequent renewal; the actual seat is so small and is 
exposed to such variations of temperature and other severe conditions 
that it tends to wear out and leak very rapidly, thus reducing the 
power and speed, rendering action uncertain and calling for frequent 


342 


GASOLINE AUTOMOBILES 


regrinding; finally, the necessity for ready accessibility for adjustment 
allows the driver, or operator, to alter the action with a consequent 
influence upon the output. 

Q. Can any of the disadvantages be overcome? 

A. The opening cannot be changed, but the noise can be reduced 
by enclosing the whole valve action in removable covers. The influ¬ 
ence of hammering in the way of wear, need for adjustment, renewal, 
leakage, etc., can be minimized by the use of tungsten steel, which is 
harder and wears much more slowly. The use of this material also 
lessens power and speed losses, uncertain action, and frequency of 
regrinding. 

Q. Is there any way in which the design can influence these? 

A. Recent tendencies and experiments have shown that with an 
arrangement for positive, or mechanical, closing of the valve, springs 
can be made very small and weak, thus eliminating the cutting 
action of the usual stiff spring on the cams and reducing the ham¬ 
mering action and the noise. 

Q. Have sleeve valves any springs? 

A. No. They are operated by eccentrics from the eccentric 
shaft, which corresponds to the camshaft in a poppet-valve system. 
These are positive at all times, that is, the sleeves are always mechani¬ 
cally operated and thus are unvarying. 

Q. What is the general shape of valve enclosures? 

A. As simple as possible. Frequently, all the valve mechanism 
is enclosed by a single rectangular plate. More usually, it consists of 
two such plates. With a single plate, a pair of, or at most three, bolts 
are used to hold it in place; with two plates, these generally have 
two bolts each. 

Valve Timing 

Q. How is the valve timing arranged? 

A. The inlet is allowed to open as soon after the upper dead 
center as the designer considers reasonable, and closes as far past the 
lower dead center as will allow the maximum charge to enter and still 
not let any of it blow out. It should be remembered that when the 
piston passes the lower center, it begins to rise and reduce the volume 
in the cylinder. Similarly as to the exhaust, it is allowed to open as 
much before the lower dead center as will insure full power, and is held 


GASOLINE AUTOMOBILES 


343 


open as long as possible, this sometimes overlapping the inlet opening 
and always passing the upper dead center. 

Q. What is the average valve timing? 

A. The timing of fifty-six American motors, including perhaps 
one hundred different models, averaged as follows: inlet opened from 
upper dead center to 21° beyond—average 10° 48b’ inlet closed from 
15° to 46° 22' beyond lower dead center—average 35° 7'; exhaust 
opened from 31° to 57° 30' ahead of lower dead center—average 50° 1 O'; 
exhaust closed from upper dead center to 21° beyond—average 9° 20'. 

Q. How does the repair man know what the correct timing is? 

A. Practically all makers give it in their instruction books and 
other literature as well as marking it upon the flywheel surface. 

Cams 

\ 

Q. How are the cams usually made? 

A. On all the better motors, the cams are formed integral with 
the camshaft, which is machined, hardened, and ground as a unit. 
This keeps the timing always the same, which is sometimes not the 
case when cams are made separate and keyed and pinned in place. 
Moreover, the integral cams are more accurate, because the machines 
which have been developed for this purpose insure absolute accuracy. 

Valve Guides 

Q. What is the valve guide? 

A. That member which forms the bearing as well as the support 
for the valve stem. Its importance can be judged from the fact that 
the guide holds the valve in line with its seat so that it seats itself 
accurately. 

Q. How are valve guides usually made? 

A. Generally, they are of cast iron and removable, being 
screwed into the cylinder from below. The diameter is made as small 
as possible and still give sufficient stiffness and strength; the length is 
made as great as possible, for the entire length of the valve guide 
is bearing surface for the valve stem. 

Exhaust Manifold 

Q. What is the influence of the exhaust manifold? 

A. To remove the exhaust gases from all cylinders as quickly 
and as thoroughly as possible. If this is not done, the burned gases 


344 


GASOLINE AUTOMOBILES 


will retard the next outflow of gas, until finally the engine may be 
stopped because it is not receiving rich enough fuel. The best form 
of exhaust manifold is the one which does this work most quickly and 
most thoroughly. 

Q. What is its general form? 

A. A long cast-iron member of round or rectangular section, 
slightly larger at the outlet end, and bolted to the cylinder casting. 

Q. How can this be improved? 

A. Recent experiments have shown that an arrangement of 
shape and size can be effected which will bring about an ejector effect 
immediately back of each exhaust orifice. This will produce a 
slight suction upon each succeeding volume of burned gas, which will 
increase the efficiency of the exhaust and thereby improve the power 
of its motor. 

Muffler 

Q. What is the purpose of the muffler? 

A. To reduce the pressure of the exhaust gases so that when 
emerging into the atmosphere they will do this without noise. As 

they emerge from the cylinders, the pressure is fairly high, and if they 

• * 

were allowed to pass immediately into the air, the noise would be 
deafening. 

Q. How is this silencing accomplished? 

A. By successive expansions, each of which reduces the pres¬ 
sure considerably. The gases come into a small central tube and are 
allowed to expand into another surrounding chamber of perhaps 
double the area, with consequent reduction of pressure. Then they 
are allowed to expand into another chamber, perhaps twice as large 
as this, with further reduction of pressure. This process is continued 
until practically all pressure is eliminated, so that the gases will 
emerge without noise. 

j 

COOLING SYSTEMS 

Q. How are explosion motors cooled? 

A. Mainly by the indirect method in which water surrounding 
the cylinders removes their heat and then is itself cooled in the radi¬ 
ator. The direct, or air-cooling, method is now used by but one 
maker, Franklin. • 


GASOLINE AUTOMOBILES 


345 


Q. What is the general cooling method? 

A. There are two methods in general use, called the natural, 
or thermosiphon, and the pump systems. The former is so-called 
because the natural increase in temperature of the water is used to 
circulate it to the radiator and back. The latter is called a pump 
system, because a pump is used to force the water around. 

Q. Are there other differences between the two? 

A. In the thermosiphon system, the difference in pressure crea¬ 
ted by the increasing temperature is so slight that all bends must 
be made very easy and all pipes made very large, so the water will 
pass easily. Also the system as a whole must be short and compact 
with radiator close to motor, and with little difference in level between 
the highest and lowest points. The added weight of larger pipes and 
their appearance just about balance the simplicity and smaller number 
of parts. 

Q. What general types of radiators are in use? 

A. The cellular (which may have square, round, or hexagonal 
cells) and the tubular form with horizontal fins sweated on are the 
two forms generally used. 

Q. How does the water circulate in these two forms? 

A. In the cellular form the water is in very thin sheets between 
the cells, with a consequently high ratio of air space to water space. 
The water is forced to follow a zigzag path to add to the cooling effect. 
In the tubular form, the water flows from an upper to a lower tank 
through the vertical tubes, which are of relatively larger diameter as 
compared with the water space in the cellular form—§ against -g^. 

Q. What is the usual form of pump? 

A. Four forms of pumps are used for water circulation: the 
centrifugal, the gear, the plunger, and the vane. The first two are 
used about equally on the majority of American pleasure cars, the 
last two having but a few adherents. 

Q. What is the latest move to improve water circulation? 

A. The use of a thermostat to control the flow of the water 
according to its temperature. This device holds the water in the 
cylinders until a certain predetermined temperature is reached, when 
it opens and allows the water to flow through the radiator and be 
cooled. By setting this so that this predetermined temperature is 
high, but not so high as to be dangerously close to the boiling point, 


346 


GASOLINE AUTOMOBILES 


the efficiency of the engine is increased, for a hot engine works better 
than a cold one and gives more power. 

Q. What is the purpose of the fan? 

A. To increase the efficiency of the radiator by drawing more 
air through it and thus cooling the water more. 

Q. How is the fan generally driven? 

A. The belt drive, using a flat or V-type belt is general because 
of its simplicity, but a few better cars have gear or chain drive; 
the latter method has increased in recent years particularly with the 
V-type motors, for in those it has been found easy to drive the fan from 
a shaft in the immediate vicinity. 

Questions for Home Study 

1. Describe in detail the timing of the Knight motor. 

2. Tell how to regulate and check up the valve action from the 
flywheel marking. 

3. How are silent-chain camshaft drives adjusted? LIow are 
gears? 

4. How is the valve-stem clearance adjusted? 

LUBRICATION SYSTEMS 

Q. What is meant when lubrication is referred to? 

A. In general, the lubrication of the engine, because that is so 
much more important than the lubrication of any other part or group 
of parts. If the engine is run without lubricant, even for a very short 
time, it is ruined. On the other hand, many of the car parts can be 
run without lubricant for days and days, yet no damage will result. 

Q. What are the most used systems for the internal oiling of 
the engine? 

A. The most used systems are: the splash, the pressure, and a 
combination of the two, known as the splash-pressure, or constant- 
level, system. The first is simple, oil being provided in troughs into 
which the connecting rods dip, thus spreading the oil all over the 
interior of the motor and lubricating everything. The pressure sys¬ 
tem forces oil under pressure to all the important bearings and surfaces 
by means of interior-drilled oil leads or special pipes. It requires a 
pump, driven from some engine shaft, one or more strainers (for the 
oil is used over and over), the special drilling or piping, a gage on the 
dash to tell the driver how the system is working, and in some cases 




GASOLINE AUTOMOBILES 


347 


an adjustable pressure valve. The splash-pressure form has the oil 
leads to the important points only. Then the excess runs down into 
the crankcase and fills troughs into which the connecting rods dip. 
In some cases, these troughs are filled by direct individual leads off 
of the main oil pipe. Then when the rods dip into the oil, all benefits 
of the splash system are obtained. The fact that the pump main¬ 
tains a constant level of oil in the troughs has led to calling this the 
constant-level system. 

Q. What pressure is used in the pressure system? 

A. Prior to the introduction of V-type and high-speed motors, 
a few pounds less than 5 was considered sufficient. Now, many 
motors have a system which works under 40, 50, 60, and even 70 
pounds pressure. The oil leads are smaller, but the amount of lubri¬ 
cant which the bearing receives is much greater than previously. 

Q. What is the external lubrication of the motor? 

A. The lubrication of the accessories, such as magneto, water 
pump, starting motor, generator, air pump, fan, etc. Practically 
all these have oil holes, oil cups, or grease cups. The last named must 
have a special heavy grease or pure mutton or beef tallow, as a thick 
lubricant is needed to resist the passage of the water and not wash 
away. Otherwise the external lubrication is fairly simple and requires 
little attention. 

Q. What are the most used types of oil pumps? 

A. Like the water pump, all forms are used but the most popu¬ 
lar are the cam-operated plunger, the gear, and the plunger. 

Q. How are these driven? 

A. By gear from any convenient shaft, as camshaft, crankshaft, 
water-pump shaft, magneto shaft, etc. When the pump is enclosed 
in the crankcase, it is almost invariably driven from one of the 
camshafts. 

Q. How are other parts of the car lubricated? 

A. Aside from clutch, transmission, rear axle, and wheels, prac¬ 
tically all parts are lubricated by means of grease or oil cups or oil 
holes. The latter are rapidly being eliminated for the sake of clean¬ 
liness. 

Q. What are possible future developments in oiling? 

A. At present, there are two tendencies noticeable, one being 
the extension of forced lubrication to many parts outside the engine. 


348 


GASOLINE AUTOMOBILES 


In the case of the Fergus car, the springs are enclosed in leather boots 
and lubricant supplied from the engine oil pump. Similarly, clutch 
and transmission are oiled from the engine pressure system. The 
1917 Marmon car is claimed to have but four or five lubricant points 
outside of the engine system. Another maker has adopted the 
leather-enclosed and lubricated springs. All these signs point toward 
less lubrication for the driver and owner to do, more points being 
included in the engine system. The other noticeable point mentioned 
has been partially covered; it is the reduction in number of points 
requiring individual attention, by other means than extending the 
engine pressure system to them. 

Q. How should graphite be used? 

A. Graphite should be used very sparingly, for a little of it goes 
a long way. It is not like grease which is used up very quickly, but 
is more or less indestructible. When a combination of graphite and 
grease is used, it will be found to last twice as long at any given point 
as the same quality of grease alone. Graphite in its very finest form, 
when introduced into the engine system, is beneficial as it seems to 
put a kind of polish, or surface finish, on the cylinders, which resists 
wear. After this has been put on, less lubricant, by at least 20 per 
cent, can be used in the engine. It should, however, be used in very 
small quantities, two tablespoonfuls to a gallon of oil being sufficient 

Q. What is its big advantage? 

A. In addition to the fact that it seems to fill up the pores 
and surface scratches of the parts on which it is used so as to give 
them a fine finish, graphite has the advantage of resisting the very 
highest temperatures very well, so that its use constitutes a safe¬ 
guard against immediate injury in case of neglect. 

Q. What are oilless bearings? 

A. There are two forms of oilless bearings, one of hard wood 
which has been impregnated with lubricant by boiling in oil, or some 
similar impregnation process, and the other is a bronze and graphite 
combination, in which about half the bearing surface consists of plugs 
or strips of pure graphite. These graphite surfaces supply the lubri¬ 
cant for the entire bearing, which never needs additional lubricant, 
so it is claimed. 

Questions for Home Study 

1. Describe the lubricating system of the Pierce-Arrow car, 


GASOLINE AUTOMOBILES 340 

t 

» 

2. How is the Cadillac eight motor oiled? Give details. 

3. What is the usual method of changing the amount of oil 
pumped, in a pressure system? 

4. Select some method of driving the oil pump, which seems 
simple to you, and describe it, telling why you selected it. 

5. How would you lubricate spring leaves, with what and how 
often? fan bearings? front wheel bearings? magneto shaft? 
differential? 

G. How do you select a good engine oil? 

FLYWHEEL GROUP 

Q. How does a light flywheel affect an engine? 

A. The engine will be easy enough to start and stop, but very 
touchy on changing speeds—too quick a change will kill it. More¬ 
over, it will not run very slowly. 

Q. How do present flywheel sizes compare with those of former 
years? 

A. Present flywheels are larger in diameter but narrower and 
lighter in weight. The increase of diameter made by the elimination 
of subframes allowed cutting down the width and weight because the 
flywheel effect is equal to its mass times its radius, so that by increas¬ 
ing the radius the mass can be reduced. 

Q. What are the usual methods of flywheel fastening? 

A. The flange forged on the crankshaft and through bolts is 
almost universal. A few motors are still made with a round crank¬ 
shaft end and a large key; or with a tapered shaft end, ahd a key, a 
nut, and a lock nut. The latter form is used when the crankcase is of 
the barrel type with removable end plates and is so made as to allow 
removal of the crankcase end plate at the rear. In some few cases 
the flywheel is made this way so as to allow putting on or taking off 
a ball bearing at the rear end of the crankshaft. 

Q. What are the markings on the flywheel rim? 

A. The timing is now generally marked on the surface of the 
flywheel to guide the owner or repair man in making adjustments or 
in assembling the engine correctly. The adjustments vary; some 
makers give the complete timing for a single cylinder, others give a 
few points for all, and still others give all the points for all the cylin¬ 
ders. The latter is the best way. 




SIDE VIEW OF PEERLESS EIGHT-CYLINDER MOTOR 

Courtesy of The Peerless Motor Car Company, Cleveland, Ohio 



















GASOLINE AUTOMOBILES 

PART IV 


CLUTCH GROUP 

TYPES OF CLUTCHES 

Classification. Principal among the indispensable parts inter¬ 
vening between engine and road wheels, and one which may be a 
source of great joy or correspondingly great wrath, according to 
whether it be well or poorly designed and fitted, is the clutch. There 
are six forms into which clutches may be divided, although not all 
of them are in general use in the automobile. Only the first four are 
widely used on automobiles. These different forms are: 

(1) Cone clutches 

(2) Contracting-band, or drum, clutches 

(3) Expanding-band, ring, clutches 

(4) Disc and friction clutches 

(5) Hydraulic, or fluid, clutches 

(6) Magnetic, or electric, clutches 

The necessity for a clutch lies in the fact that the best results 
are obtained in an automobile engine when run at constant speed. 
In as much as the speed of the car cannot, from the nature of its use, 
be constant, it requires some form of speed variator. This is the 
usual gear box, or transmission, but, in addition, there is the necessity 
of disconnecting it from the motor upon starting, since the engine 
cannot start under a load. There is also the necessity for disconnect¬ 
ing the two when it is desired to change from one speed to another 
either by way of an increase or a decrease. So, also, when one wishes 
to stop the car, there must be some form of disconnection. There 
are, then, three real and weighty reasons for having a clutch. 

Requirements Applying to All Clutches. In a serviceable clutch 
there are two general requirements which are applicable to all forms. 
These are gradual engagement and large contact surfaces, although 
the latter requirement may be made to lose much of its force by 



352 


GASOLINE AUTOMOBILES 


SPIDER- 



/?- 




CLUTCH 

ENGACINC SPRING 



FLYWHEEL 
-FACING 
-FACING SPRING 


MOTOR 
CRANK SHAFT 


IL LEAD 


making the surfaces very efficient. In the cone clutch, gradual 
engaging qualities are secured by placing a series of flat springs under 
the leather or clutch lining. By means of these springs, acting against 
the main clutch spring, the clutch does not grab, since the large 
spring must have time in which to overcome the numerous small 
springs. In this way, the engagement is gradual and the progress of 

the car is easy as well as 
continuous. 

The specific neces¬ 
sity in a cone clutch, 
whether it be direct or 
inverted, is a twofold one 
—sufficient friction sur¬ 
face and proper angu¬ 
larity. The latter, in a 

t j / 

way, affects the former, 
as will be discussed more 
in detail later. The an¬ 
gularity varies in practice 
from 8 to 18 degrees. 

Cone Clutch. The 
cone clutch consists of 
two members, one fixed 
on the fivwheel or other 

t/ 

rotating part of the en¬ 
gine and the other fixed 
to the transmission shaft. 
The latter usually slides 
upon the shaft so as to 
allow engagement and disengagement. A spring holds the two 
together or apart, according to the type of clutch used. When 
the ^mailer-diameter member is spoken of, it is usually called the 
male member, while the part of larger size is spoken of as the 
female member. 

The cone type is made in two different varieties: one in which 
the male member enters the female naturally at the open end is 
called the direct cone type; in the other, the male member is set within 
the structure of the female and is pressed outward toward the open 


Fig. 246. Section through Studebaker 
Direct Cone Clutch 

Courlesy of St udebaker Corporation, Detroit, Michigan 























GASOLINE AUTOMOBILES 


353 


end to engage it. This is called the inverted, or sometimes the 
reversed, cone clutch. 

A great disadvantage of the inverted form is that the spring must 
be carried between the two cones, which means that it is inside where 
it cannot be reached for adjustment. This form causes trouble in 
assembling because the male cone must be put in place with the 
spring between it and the flywheel before the female can be set into 
its place and bolted up. These two big sources of trouble have caused 
designers to turn to the direct type more freely, as it lends itself 
readily to an external 
adjustment. If the spring 
is outside, it is easily put 
into place and as easily 
taken out. 

An excellent exam¬ 
ple of the direct cone 
clutch is seen in Fig. 240, 
which shows the Stude- 
baker clutch in section. 

The noticeable point 
about this clutch is its 
simplicity. It will be 
noted that the spring is 
entirely enclosed, so that 
when it needs adjusting 
the repair man must 
open the universal joint 
and operate the bolt A which regulates the tension of the spring. 

Another good example of the simplicity of the cone clutch is seen 
in Fig. 247, which is an aluminum member with bosses cast for cork 
inserts. Between the inserts may be seen the flat heads of the copper 
rivets which hold the clutch facing in place. Obviously, this has the 
same disadvantage of internal, and thus inaccessible, spring. 

In the cone type of clutch, shown in Fig. 248, the inaccessible 
spring is avoided. In addition, a number of small springs are used in 
place of one very large and very stiff one. The ease of adjustment 
and the greater ease in handling the springs make this clutch a much 
better design for average use from the repair man’s point of view. 



Fig. 247. Direct Cone Clutch with Cork Inserts 





354 


GASOLINE AUTOMOBILES 


An example of the inverted-cone type is shown in Fig. 249, which 
shows the clutch on the four-cylinder Stearns-Knight. This type has 
an odd number of small springs equally spaced around the clutch, 
but these cannot be adjusted from the outside. 

Contracting=Band Clutch. A short consideration of the band 
style of clutch shows that this does not differ radically from the ordi- 
nary band brake, either in construction, application, or actual work¬ 
ing. The difference in the 
two lies in the fact that the 
band, as a clutch* is de¬ 
signed to transmit power 
with as little loss as possi¬ 
ble, while the band as a 
brake is designed to absorb 
the forward energy of a 
moving vehicle in the short¬ 
est possible space of time, 
i.e., to waste as much power 
as possible. 

Fig. 250 shows a typical 
contracting-band clutch. It 
will be noted that this clutch 
has the two parts, or sec¬ 
tions, of the band united at 
the bottom and two oper¬ 
ating levers pivoted at the 
top, where a single conical- 
shaped cam moves both 
outward and tightens the 
bands on the drum. 

The usual place in 
which the band clutch is 
found is in connection with a planetary transmission. There the band 
is always used, and there it reaches its simplest form, that of the plain 
band wrapped around the drum. One end is fixed and the other 
attached to the braking, or more correctly, the clutching, lever. A 
plain pull on this effects the clutching action. A more modern and 
more efficient form has one end of the band attached to one extremity 



Fig. 248. Direct Cone Clutch with Small Springs and 
External Adjustment 

Courtesy of Willys-Overland Company, Toledo, Ohio 












































































GASOLINE AUTOMOBILES 


355 


of the, clutching lever, while the other end of the band is fastened to 
the middle of this lever. The clutching pull comes upon the upper 
extremity of the lever. Then the band acts to aid in clutching itself, 
i.e., a scissors action is obtained, and the required pull is lessened. 

This construction can be seen quite plainly in Fig. 287, which 
shows the planetary transmission and bands used on Ford cars. In 
this, the low- and reverse-speed 
bands are shown in full. This 
is of particular interest as Mr. 

Ford is now the only American 
maker using the planetary form 
of transmission, all other makers, 
even of very low-priced machines 
—some below the Ford price— 
having gone to the selective 
sliding-gear form. 

Expanding=Band, or Ring, 

Clutch. The expanding-band 
clutch finds favor among few. 

Like the contracting band, which 
is very similar to the band form 
of brake, the expanding band is 
much like the expanding type of 
brake, except that the clutch is 
used to form the connection be¬ 
tween two rotating parts. Viewed 
from the standpoint of pure 
engineering, the expanding band 
is little different from the cone 
type of clutch, granting that the 
angularity of the operating cam 
is the same as that of the cone. 

Much depends upon how the band is expanded. This expansion 
is usually accomplished by means of screws, which may be either 
right-handed or left-handed or both. 

Another form is expanded by a right-and-left screw operated 
by a lever. The lever, in turn, is moved by a pair of sliding collars on 
the main-clutch shaft, the clutch foot pedal moving these forward. 



Fig. 249. Inverted Cone Clutch Used on 
Stearns-Knight Four-Cylinder Cars 

Courtesy of F. B. Stearns Company, 
Cleveland, Ohio 




























































































356 


GASOLINE AUTOMOBILES 


Disc Clutch. With its advent in 1904, the multiple-disc clutch 
has steadily grown in popularity, until today it is looked upon as the 
most satisfactory solution of the difficult clutch problem. Designers 
who have once adopted it, seldom, if ever, go back to another form, 
while of the new cars coming out from time to time nearly three- 
fourths are equipped with some form of disc clutch. 

Popularity Compared with Other Forms. Statistics for 1914 
showed that the disc form of clutch was easily the most popular type. 
Of 230 different chassis for 1914, 119 were equipped with disc clutches, 
97 with the cone, 9 with a contracting-band type, and but 5 with an 
expanding-band form. The relative figures for 1916 were about 94 



Fig. 250. Typical Contracting-Band Clutch 


disc, 81 cone, no contracting band, no expanding band, and 1 electric. 
This would give the first-named approximately 54 per cent of the total. 

Two Forvis of Same Make. Reference to the types of clutch 
brings to mind the relative advantages of the two leaders, the cone 
and the disc. These are presented in a very striking manner in 
Figs. 251 and 252, which show the cone and disc clutches used inter¬ 
changeably by the Warner Gear Company, Toledo. These clutches 
are designed to be interchangeable, consequently the general layout 
is the same. It will be noted that the cone is somewhat simpler than 
the disc, as it has fewer parts which take up room. The design is such 
that the internal spring of the cone can be adjusted from the outside 



























































































































GASOLINE AUTOMOBILES 


357 


as can the outside spring of the disc. An interesting point in this 
connection is that the transmissions also are interchangeable, although 
the type, Fig. 252, with roller bearings is intended for a moderately 
heavy passenger car, while that in Fig. 251 is for lighter work. 

Simple Types. The simple types differ in number and shape of 
discs, method of clutching, material, and lubrication; but in principle 
all are alike. This clutch is one in which the flat surfaces properly 
pressed together will transmit more power with less trouble than any 



Fig. 251. Typical Three-Speed Gearset with Cone Clutch for Unit Power Plant 
Courtesy of Warner Gear Company, Toledo, Ohio 


other form. By multiplying the number of surfaces and making 
them infinitely thin, the power transmitted may be increased indefi¬ 
nitely. That this is not idle fancy is shown by a number of very 
successful installations of 1000 horsepower and over in marine service. 

The minimum number of plates in use is said to be three, but 
very often the construction of a three-plate clutch is such that one oi 
two surfaces of other parts are utilized, making it a two- or even one- 
plate clutch in reality. In the Warner clutch, shown in Fig. 252, 
there are really but two clutching surfaces, the face of the inner plate 











































































































































358 


GASOLINE AUTOMOBILES 


against the flywheel and the outer face against the engaging disc. 
Both plates are faced with suitable friction surface but it really is a 
one-disc clutch. 

Multiple-Disc Clutches. The modern tendency in disc clutches, 
however, is away from those of few plates requiring a very high 
spring pressure—since the friction area is necessarily limited 
toward the multiple-disc variety, in which a very large area is 
obtained. The large area needs a very light spring pressure, and 



Fig. 252. Typical Three-Speed Warner Gear Box Shown in Fig. 251, but with Disc Clutch 


consequently it is easier to engage and disengage the clutch. For this 
reason, the multiple disc is becoming more popular with owners and 
drivers than the variety requiring the extra-heavy effort. The con¬ 
struction of the three-plate disc clutch does not differ radically from 
one maker to another. Three fingers are used to clutch and declutch 
generally, the amount of movement being adjustable. A single spring 
of large diameter and large-size wire is generally used, and sheet steel 
is used for one-half the clutch plates. Between the three-plate and 
multiple-disc are many gradations. 






















































































































































GASOLINE AUTOMOBILES 


359 


In the true multiple-plate clutch, there are three general varieties 
met with in practice: the metal-to-metal with straight faces; the 
metal-to-metal with angular or other shaped faces designed to 
increase the holding power; and the straight-face kind in which metal 
does not contact with metal, one member either being lined with a 
removable lining or fitted with cork inserts. 

Metal-to-Metal Dry-Disc Type. The metal-to-metal method has 
the additional advantage of having the central part within which the 
clutch is housed very small in diameter, so that the portion of the fly¬ 
wheel between the rim and the clutch housing may be made in the 



Fig. 253. Multiple-Disc Clutch and Transmission of Winton Cars 
Courtesy of Winton Motor Car Company, Cleveland, Ohio 


form of fan spokes that convert it into a fan which serves to cool the 
motor better. 

As the various examples of disc clutch shown would indicate, 
the designer has had his choice between a few large discs and a large 
number of small ones. If he chose the former, the clutch could be 
housed with in the flywheel, but that would make it inaccessible. If he 
chose the latter, the clutch could not be kept within the flywheel 
length. A separate clutch housing would be a necessity, but the 
clutch could be made accessible and flywheel fan blades could be used. 

Another example of the plain metal-to-metal disc clutch is shown 
in Fig. 253. In this case also the clutch is not housed in the flywheel, 










































































































































































GASOLINE AUTOMOBILES 


360 


as in most of the preceding examples of this form of clutch, but in the 
forward end of the transmission case, that is, instead of motor and 
clutch forming a unit, the clutch is a unit with the transmission. It is 
claimed that this position makes it more accessible, since it brings the 
clutch directly under the floor boards of the driver's compartment 
where it can be lubricated better. The lubrication is effected through 
communication with the gear part of the case, which is always filled 
with lubricant. 

In the figure it will be noted that there are 13 driven discs, with 
key ways, which hold them to the driven drum. Note that the drum 
is held to its shaft by means of a pair of large set screws. The clutch¬ 
ing springs are of small diameter and size, spaced equally around the 
periphery of the discs; each disc is enclosed in a small and thin metal 
casing. Attention is called also to the universal joint shown. This 
joint forms the rear end of the driving connection with the flywheel, 
which will be referred to later. These discs are flat-stamped out of 
sheet steel with the proper keyways for internal or external holdings. 

Use of Facings. The more modern disc clutch has two sets 
of sheet metal discs, one of which is faced on one or both sides with 
a special material. Without a single exception, all the disc clutches 
shown have had plain discs against plain discs. This makes a simple 
and fairly inexpensive construction, but one that is not very efficient. 
The most recent tests have shown that metal against metal gives a 
coefficient of friction of but .15, which is reduced to .07 when the 
surfaces become oily or greasy. With one of these contacting faces 
lined with leather, the coefficient rises to .23 when drv and to .15 when 
oiled. Again if fiber is used for the facing, the coefficient becomes, 
respectively, .27 and .10, while with cork or with cork and leather, it 
becomes, respectively, .35 and .32. Here is a very apparent reason 
for (1) facing the clutch discs, and (2) running them dry. 

By going over these figures, it will be noted that discs with 
almost any form of facing will show an increase in efficiency over the 
same discs without facing, varying from 60 up to almost 300 per 
cent. Again, any form of disc clutch, faced or otherwise, will show 
a much higher coefficient when dry than when oiled and thus a 
greater efficiency. These two facts point out the obvious reasons 
for the modern tendency toward the multiple-disc clutch, faced and 
running dry. 


GASOLINE AUTOMOBILES 


361 


To present an example of the faced type, Fig. 254 shows the 
multiple-disc clutch of the eight-cylinder V-type Cadillac. In this 
illustration the eight driving discs can be seen with the facing on 
each side of each one. This facing is of wire-mesh asbestos, and 
between each pair of discs comes a plain driven disc, so that it has a 
facing of the asbestos against each side of the metal which it grips. 
I be keys holding the inner discs to the shaft can be seen on the 



Fig. 254. 1917 Cadillac Clutch and Transmission, Showing New Clutch Drive 

Courtesy of Cadillac Motof Car Company, Detroit, Michigan 


end of the housing, while the slots into which the keys project can 
be seen on the discs. By examining the group closely, the driven 
plain discs can be seen between each pair of the drivers. The 
method of driving these discs through a multiplicity of keys and 
grooves is unusual, but it is a good example of Cadillac thoroughness. 
Fig. 254 also shows the pedals and the exterior of the clutch case 
where it bolts up to the engine. This indicates how a unit power 
plant simplifies the control group and eliminates parts. 




362 


GASOLINE AUTOMOBILES 


Floating Discs a Novelty. The clutch on Locomobile cars, 
shown in section in Fig. 255, is very much like the Cadillac just 
shown, except for the novel feature that the fabric facings are not 
attached either to the driving or to the driven discs but float between 
them. This fabric, usually a woven asbestos material with a central 
core of interwoven metal wires, instead of being attached to both 
sides of every other disc or to one side of every disc, is not attached 
at all. The rings for the fabric discs are made up in the form of 
annular rings. They have the same inner diameter as the inside of the 



Fig. 255. Floating Dry-Disc Clutch Used on Locomobile Cars 


driving discs and the same outside size as the driven discs; conse¬ 
quently, assembling one of these clutches is simply a question of 
piling first a driven disc, then a fabric, then a driving disc, and so on. 

The fact that the fabric rings are not united to either of the 
metal discs allows them to free themselves with remarkable rapidity 
so that either on engagement or on declutching the action is very quick. 

Greater Poiver Transmitted by Surfaces Not Plane. To increase 
the power transmitted by a clutch of given size, either the number of 
plates must be increased or the form of the surface changed. The 
latter method was followed on the clutch of the French car “Ours.” 







































































































































GASOLINE AUTOMOBILES 


363 


I lie discs of this unusual clutch had a perfectly flat outer portion 
and a conical inner portion, only the latter taking part in the trans¬ 
mission of power. In this disc form, then, we have the advantage 
of the disc economy of space, together with the advantages of the 
cone clutch and the additive gain of running in a bath of oil. 

Another form utilizing this principle, and one that is more widely 
used, is that known as the Hele-Shaw” so named from its inventor, 
the famous English scientist, Dr. H. S. Hele-Shaw. This is essen¬ 
tially flat disc, as shown at A, Fig. 256, with a ridge B at about 
the middle of the friction surface; this ridge consists of a portion 



Fig. 256. Hele-Shaw Disc Clutch, Showing Cone Surfaces 


of the surface, which has been obtruded during the stamping process 
in such a way as to leave the surface of the ridge in the form of an 
angle of small height. The angle used is 35 degrees, and this value has 
been determined upon experimentally as the best. Fig. 256 shows a 
cross-section through an assembled clutch, which reveals the clutch 
angle very plainly. In use, the ridges nest one on top of the other; 
and in the extreme act of clutching, not only the flat surfaces but 
both sides of the ridge are in contact with the next plate. Thus, not 
only is the surface for a given diameter increased, but the wedge 
shape is also taken advantage of. 































































































364 


GASOLINE AUTOMOBILES 


Hydraulic Clutches. All the methods of engaging and dis¬ 
engaging the engine at will, as discussed before, have been of a 
mechanical nature. The hydraulic clutch, on the other hand, par¬ 
takes more of the fluid nature, although it is operated by mechanical 
means. Ordinarily, it is in the nature of a pump with a by-pass, 
the pump working at ordinary speeds to force the heavy liquid, 
usually glycerine, through the by-pass. To clutch up tightly, how¬ 
ever, the by-pass is closed and, the liquid being unable to circulate 
while the pump continues to operate, the whole device is rotated as 
a unit. In this case it operates just as any other clutch, but, due to 
the sluggish action of the fluid, it is slower to respond. Then, too, 
the grave question of leakage is always present, and the smallest leak 
puts the clutch entirely out of use. These disadvantages, together 
with the necessary complications, have retarded the development of 
the hydraulic form so that there are few of that type in use today. 

Magnetic Clutch. All the foregoing clutches present in one 
form or another very complicated devices for freeing the transmission 
shaft from the engine shaft, but the magnetic clutch is a device which 
has simplicity for its foremost argument. The magnetic clutch 
consists primarily of three parts: the field, usually in the form of a 
ring; the armature, always of ring shape; and the oil casing shaped 
to accommodate the other parts, its function being that of a cover. 
The armature is a simple cast-iron plate of rectangular section, 
adapted to be drawn into engagement with the field when the latter 
is energized. 

The field, on the other hand, is made up of the back plate, 
the inner and outer field rings, the magnetizing coil, and the contact 
rings. In operation, the accelerator is energized by closing the 
electrical circuit, which sends a current through the field. This 
magnetism attracts the armature, which then moves laterally, clos¬ 
ing the very small gap between the two. The oil in which the 
whole clutch works prevents it from taking hold suddenly, or grip¬ 
ping, but as this oil film on the two surfaces is gradually squeezed 
out, the clutch as gradually takes hold. 

New Electric Generating Clutch. So great has been the interest 
in the various electrical mechanisms in the automobile, and so 
quickly has the public taken up with all these that this has stimu¬ 
lated an entirely new invention, called by its maker, the Vesta 


GASOLINE AUTOMOBILES 


365 


Accumulator Company, Chicago, a centrifugal electric-generating 
clutch. This name gives a little clue to its action, which is that of a 
combination of the usual friction clutch and that of the electric- 
magnetic drag between armature and fields of any electric machine. 

In addition to its clutching feature, its ability to drive when 
partially clutched makes it, in effect, a transmission, so that it is 
designed to replace the usual clutch, gearset, flywheel, electric gen¬ 
erator, and starting motor. It is composed of two parts: an arma¬ 
ture, which becomes the flywheel; and a field mounted on the pro¬ 
peller shaft. The former carries an internal commutator, and the 



Fig. 257. Field Unit of the Vesta Centrifugal Electric Clutch 
Courtesy of Vesta Accumulator Company, Chicago, Illinois 


latter carries brush holders which hold brushes against the commutator. 
These brushes are mounted so that the centrifugal force of rotation 
increases the force with which they press against the commutator. 
Thus there is a variation from practically no contact up to the maxi¬ 
mum, at which point the centrifugal force is so great that field and 
armature revolve as a solid unit. 

This construction is well indicated in the two illustrations of this 
device, Figs. 257 and 258. Fig. 257 shows the field unit mounted on 
the propeller shaft in which F is one of six field poles, B a brush, and 
C one of the collector rings. Fig. 258 is an external view which shows 









366 


GASOLINE AUTOMOBILES 


the clutch assembled. In this illustration the brushes B are shown 
pressed out against the commutator by the centrifugal force. 

An automobile built in France—the Ampere—uses the electric¬ 
generating clutch construction exclusively, the master clutch being 
dispensed with in favor of an individual-clutch transmission. The 
differential is dispensed with, and in its place a pair of magnetic 
clutches—one for each wheel—are used. The differential action is 



Fig. 258. Assembled Vesta Electric Clutch 
Courtesy of Vesta Accumulator Company, Chicago, Illinois 

obtained on curves by decreasing the current to the clutch on the 
inner wheel up to a certain point, at which it is cut off entirely. This 
gradual reduction and cutting off of the current is accomplished 
automatically by the movement of the steering wheel. 

DETAILS OF CLUTCH OPERATION 

Methods of Operation. Practically all modern clutches are 
operated by means of a special pedal moved by the left foot. The 
pedal is connected to the internal member by means of rods and levers, 






GASOLINE AUTOMOBILES 


367 


which compresses the clutch spring or springs and allows the clutch 
members to separate. This throws the clutch out. To throw it 
back in, remove the foot pressure from the pedal, and the springs 
again exert pressure and force the parts together. This action 
causes them to take hold. There was a time when a considerable 
number of cars had the clutch so constructed that the pedal held it 
in and the springs threw it out, just the reverse of the present plan. 
This method is no longer used, as it necessitated a constant pressure 
on the pedal while driving—a very fatiguing process. 

Gradual Clutch Release. The Dorris clutch, made by the Dorris 
Motor Car Company, St. Louis, Missouri, Fig. 259, is a new arrange¬ 
ment of the clutch pedal, 
and its operation is such 
that the clutch is released 
or thrown out with very 
light pressure on the 
pedal. Pressure on the 
pedal A is transmitted 
bv the shorter lever arm 
B, thus greatly increas¬ 
ing the leverage. This 
pressure is transmitted to 
lever C and through it to 
lever D, these two being 
hung on the frame cross 
member E. As C is much 
longer than D, there is 
another multiplying ac¬ 
tion here. This does not 
act directly upon the 
clutch but upon the upper 
end of the clutch shifter 
F, which is attached to the clutch at G and pivoted at its lower 
end II —here again in a multiplying action. The net result of these 
three multiplications is a combination which will release the strongest 
and stiffest clutch with a very slight pressure of the foot. 

Clutch Pedals. It has been the general practice in the past to 
have the clutch pedals separate and distinct, with the service-brake 



Fig. 259. Multiplying Lever of Dorris Clutch to 
Make Pedal Pressure Light 

Courtesy of Dorris Motor Car Company, St. Louis, Missouri 





































































368 


GASOLINE AUTOMOBILES 


pedal on a concentric shaft occasionally. Now, however, the rapidly 
growing practice of simplification and elimination, combined with the 
wide use of the unit power plant, is eliminating the so-called clutch 
shaft with its bearings and fastenings to the frame, to the clutch 
operating yoke, and to many other parts. As the Cadillac illustra¬ 
tion, Fig. 254, shows and as the Buick drawing, Fig. 260, shows even 
better, all these shafts, rods, and fastenings can be eliminated and the 
pedals and levers mounted directly on or in the power unit. In the 
Buick illustration, the foot brake has a simple rod connection from 
the ear A on the pedal to the brake-operating system, while the 



Fig. 260. Unit Power Plant of New Small Buick Four 
Courtesy of Buick Motor Com-pany, Flint, Michigan 


hand brake has a similar connection from the extended lower end of 
the rod B to that brake-operating system. In this simple way, 
perhaps 40 or more pieces are eliminated and their weight saved. 

Clutch Lubrication. As has been previously pointed out, some 
clutches run in oil, while others run dry. The former type must be 
kept filled with lubricant at all times. The general plan in such a case 
is to provide a lead from the engine oiler when the clutch case is 
separated from the engine case or a connecting means when the two 
are in one case. In addition to the actual clutching members, there 
is practically always a sliding member, which must have lubricant of 
some form, while the thrust bearings to take the thrust of the clutch 































































GASOLINE AUTOMOBILES 


369 


springs must be cared for. Generally, these two cases are cared for 
by a pair of grease cups, which are visible in Figs. 247 and 249. 
The operating rods are lubricated usually by means of small oil holes, 
either drilled directly into the part or covered with a small oil cup. 
In those cases in which the clutch runs in oil, it will be noted that a 
filling plug is provided, by means of which additional lubricant can 
be poured into the casing, Fig. 256. 

Cdutch-bearing lubrication is highly important, particularly with 
clutches like the cone which must be kept free from lubricant and the 
dry disc in which lubricant is not used. Where the clutch itself 
runs in oil, it is a simple matter to lubricate the bearings, but in 
the other cases, oil or grease must be provided from one of three 
places: from a prolongation of the engine oiling system, as shown in 
Figs. 246 and 251; from the outside—generally by means of grease 
cups—as just discussed; or from the transmission end. The last 
form is used only in unit power plants; combinations of clutch and 
transmission, as shown in Fig. 253; and in cases, Fig. 256, where 
the construction allows a grease or an oil cup attachment at the 
transmission end, the transmission itself being some distance away. 

Clutch Bearings. The need for bearings in a clutch depends 
somewhat upon its nature and location, but regardless of these a 
thrust bearing is needed for the clutch spring. To explain this 
briefly, it is known that action and reaction are equal, and opposite 
in direction. For this reason, when a clutch spring presses the discs 
or parts together with a force of, say, 100 pounds, there is exerted 
in the opposite direction this same force of 100 pounds. In order to 
have something for this to work against, a bearing is used, and since 
it takes up this spring thrust, it is called a thrust bearing. Not all 
bearings are fitted to take thrust, as the majority are designed for 
radial loads only. For this reason a special design is needed. 

When the clutch is incorporated in the flywheel, two additional 
bearings — one for the end of the crankshaft and another for the 
transmission or driven shaft—are generally needed. The bearings 
will be noted in Figs. 246, 248, and 249, although the transmission- 
shaft bearing does not have the clutch combined with the engine but 
rather with the transmission. In the majority of cases, it will be 
found that a means of fastening the end of one shaft has been worked 
out so as to eliminate one bearing. This accounts for the large 



370 


GASOLINE AUTOMOBILES 


number which show but two—the thrust and one other. In looking 
back over the clutches, it will be noticed also that nearly all the bear¬ 
ings are of the plain ball form. This is due in large part to the fact 
that the plain ball bearings take up the least room for the load carried, 
both in diameter and width—a contributing reason being the fact 
that in many cases one of the shafts or parts can be formed to take 
the place of either the inner or outer ball race. 

Clutch Adjustment. Adjusting a clutch, as a rule, is not a 
difficult task as there are but two possible sources of adjustment—the 
throw or movement of the operating pedal or lever and the tension 
of the spring. An adjustment is generally provided for each. When 
the fullest possible throw of the pedal does not disengage the clutch, 
an adjustment is required to give a greater throw. If the throw is 
correct, but the clutch takes hold too quickly and vigorously, the 
spring pressure can be lessened somewhat to soften down this action. 
On the other hand, when dropped in quickly, if it takes hold slowly, 
more spring pressure is needed, and it should be tightened. 

Clutch Accessibility. Clutches are made accessible in two ways: 
by their location on the car and by the relative ease with which they 
can be removed. Accessibility as to location is less in the various 
combinations, such as in the unit power plant, housed within the 
flywheel, or combined with the transmission. Ease of removal is 
determined by the number and location of the joints (usually uni¬ 
versal) used with the clutch. 

CLUTCH TROUBLES AND REMEDIES 

The very fact that the clutch is a more or less flexible, or rather, 
variable, connection between engine and road wheels makes it 
necessary that it be kept in the best of shape. It is rather surprising 
to the novice with his first clutch trouble to have his motor racing 
at the highest possible speed and to find his car barely moving, but 
to the experienced driver it is humiliating. 

Slipping Clutch. Slipping is the most common of clutch trou¬ 
bles. This is brought about in a cone clutch by oil, grease, or other 
slippery matter on the surface of the clutch and can often be cured 
temporarily by throwing sand, dirt, or other matter on the clutch 
surface, although this is not recommended. Many times, the 
clutch leather, or facing, becomes so glazed that it slips without any 


GASOLINE AUTOMOBILES 


371 


oil or grease on it. In that case it is desirable to roughen the surface. 
This may be done by taking the clutch out, cleaning the surface with 
kerosene and gasoline, and then roughing-up the surface with a file 
or other similar tool. 

In case it is not desired to take the clutch out, or when it is very 
inaccessible, the clutch surface may be roughened by fastening the 
clutch pedal in its extreme out position with some kind of a stick, 
cord, or 'wire, and then roughing the surface, as far in as it can be 
reached, with the end of a small saw, preferably of the keyhole type, 
as shown in Fig. 261. Before starting this repair, it is well to soak 
the leather with neat’s-foot oil. This softens the leather and makes 
the roughening task lighter. 

Many drivers make the mis¬ 
take of driving with the foot 
constantly on the clutch pedal. 

This wears the leather surface 
and helps it to glaze quickly. 

The constant rubbing from fre¬ 
quent slipping makes the leather 
hard and dry. 

When a metal-to-metal oiled 
clutch slips, the trouble usually is 
in the clutch spring, which is too 
weak to hold the plates together. To remedy slipping with this 
type, it is necessary to tighten up the clutch-spring adjustment. 

Clutch troubles are not always so obvious. In one instance, 
the clutch slipped on a new car. In the shop, the clutch spider 
seemed perfect and properly adjusted, also the spring, but to make 
sure, a new clutch was put in. Still the clutch slipped. To test it 
out still farther, the linkage was disconnected right at the clutch 
and then it held perfectly, showing that the trouble was in the link¬ 
age. On examination one bushing was found to be such a tight fit 
that it would not allow the pedal to move freely enough to release the 
clutch fully. When this was relieved a little, the clutch acted all right. 

Replacing Clutch Leathers. Clutches offer many chances for 
trouble. The most frequent causes are the wear of leather facings 
with the attendant loss of power, and weak springs. Weak springs 
may be cured by screwing up on the adjusting nut or bolt provided. 


SAW 


LEATHER 

FACING 


CLUTCH 

CONE 


FLYWHEEL 



Fig. 261. Method of Roughing-Up Clutch 
Leather with Saw 

































372 


GASOLINE AUTOMOBILES 


Slippery leather may also be corrected by washing first with gaso¬ 
line and then with water, finally roughing the surface with a coarse 
rasp and replacing only after the leather is thoroughly clean. Dry 
leather is fixed by soaking in water or neat’s-foot oil. It should be 
replaced while still moist, and copious lubrication will keep it soft. 

The greatest problem in replacing a worn, charred, or otherwise 
defective leather lies in getting the right layout for the form of the 
new leather the first time. It must be remembered that the surface 
is a portion of a cone and, therefore, its development is not easy. 

It is attacked in this man¬ 
ner: Prepare the cone by 
removing the old leather 
and all rivets, cleaning out 
the rivet holes, and provid¬ 
ing new rivets. Measure the 
cone, taking the diameters 
at both the large and small 
ends and also the width. 
Take a large sheet of paper 
and lay off upon it a figure 
similar to A BCD, Fig. 262, 
drawn to exact scale and 
having for its dimensions 
the three measurements 
just obtained, viz, the large 
and small diameters and the 
width of the cone. This 
figure represents the projec¬ 
tion of the cone in a flat 
plane. Bisect the line AD 
and draw the center line EF at right angles to AD. Prolong the 
two tapered lines AB and DC until they meet the center line as at G. 

The point G represents the apex of the cone if it were complete, 
and hence any circular are with the correct radius, drawn from this 
point as a center, will be a correct projection of the development 
of that portion of the conical surface. With GA and GB as 
radii, draw the two circular arcs IIADJ and IBCK, also draw the 
radial lines 111 and JK to pass through G. The enclosed figure 


rr 



Fig. 262. Diagram Showing How to Cut Clutch 
Leathers 











GASOLINE AUTOMOBILES 


373 


HIBCKJDAH may then be cut out and used as a pattern from 
which to cut out clutch leathers. If the distances AH and DJ be 
made approximately equal to or slightly more than AD, the pattern 
will a little more than encircle the cone clutch. 

After the leather has been cut out, it should be prepared by 
soaking in water or oil, according as its surface is fairly soft or rather 
harsh. In either case, it must be well soaked, so as to stretch easily. 
In putting it on the cone, one end is cut to a diagonal, laid down on 
the cone, and riveted in place. Next, the leather is drawn down 
tightly past the next pair of rivet holes, which are then driven into 
place. This is continued until the strip is secured. The leather is 
now wetted again, for, if allowed to dry off immediately, the shrinking 
action will break it out at most of the rivet holes and render it use¬ 
less. By drying it out gradually, a taut condi¬ 
tion may be arrived at without this danger. 

Handling Clutch Springs. Clutch springs, 
like the valve springs mentioned previously, 
are mean to handle and compress. The best ^ 
way is to compress and hold them compressed 
until needed. For this purpose, a rig similar 
to that described for valve springs should be 
made but of stiffer stronger stock. A very 
good one can be made from two round plates, 
one small, and the other of larger diameter with 
a pair of L-shaped bolts through it. The 
spring is placed between the two, with the 
ends of the L’s looped over the smaller plate, and then, by tight¬ 
ening the nuts on the bolts, the spring is gradually compressed. 

An excellent device for holding clutch springs consists of a 
simple pair of metal clamps which are joined together by three or 
more short metal bars, as Fig. 263 shows. If one particular clutch 
spring is handled continuously, the length can be made to fit this 
best, otherwise it will have to be made of any convenient length. 
The inside diameter of the clamps when fully open is greater than 
the outside diameter of the spring. The clamp is set in a vise or on 
a drill press and the spring set inside of it. Then the spring is com¬ 
pressed by working the vise handle or by lowering the drill-press 
spindle. When compressed down to the length used in the car, the 



Fig. 263. Type of Clutch 
Spring Holder Which 
Works by Friction 

Courtesy of "Motor World" 















































































374 


GASOLINE AUTOMOBILES 


ends of the clamp are tightened and the spring is held by friction. 
Then the spring can be handled readily, using one of the metal bars 
as a handle. It is put into place, and then the retaining screws can 
be loosened and the clamp removed. 

Fierce Clutch. A fierce clutch is one that does not take 
hold gradually but grabs the moment the clutch pedal is released. 
In a metal-disc clutch, this is caused by roughened plate surfaces 
and insufficient lubricant, so that, instead of the plates twisting 
gradually across each other as the lubricant is squeezed out from 
between them, they catch at once and the car starts with a jerk. 
On a cone clutch, this fierceness is produced by too strong a spring, 

too large a clutching sur¬ 
face in combination with a 
very strong spring, or a hard 
or burned clutch surface or 
both. 

Ford Clutch Troubles. 

There are now so manv 

t/ 

Fords in use that the aver¬ 
age repair man feels justified 
in making special apparatus 
or tools to save time or 
work in Ford repairs. For 
one thing, the clutch-disc 
drum frequently needs 
removal and this is a diffi¬ 
cult job. By means of a simple rigging, however, consisting of a plate 
and a few bolts, it can be taken off in a few moments and with little 
trouble. It will be noted from Fig. 264 that the rigging is but a modi¬ 
fied form of wheel puller. It consists of a J-inch plate of steel with 
three holes drilled in it for three bolts. The two outside ones have 
T-head ends and have to be specially made, and made carefully, 
as this T-head must slip through either one of the oval holes in 
the web of the drum. When this is done, it is straightened up so 
as to stand at right angles to the drum and is thus in a position 
to press firmly against the drum from the inside. There are nuts 
on the center bolt on both sides of the plate, but the drawing shows 
only that on the outer end. When the T-bolts are in place, the 



Fig. 264. Simple Rigging for Removing Ford 
Clutch Disc 


I 

















































GASOLINE AUTOMOBILES 


375 


center bolt, which is slightly pointed and preferably hardened on 
the end, is screwed down so as to come into contact with the end 
of the clutch shaft. After tightening the center bolt, the T-head 
bolts are tightened until they pull the drum off the shaft. 

Clutch Spinning. A trouble which is bothersome but not 
dangerous is clutch spinning. This is the name applied to the 
action of the male clutch member when it continues to rotate, or 
spin, after the clutch spring pressure has been released. With the 
male member connected up to the principal transmission shaft and 
gear, as is often the case, these members continue to rotate with it. 
This gives trouble mainly in gear shifting, for the member which is 
out of engagement is considered to be at rest or rapidly approaching 
that condition. When at rest, it is an easy matter to mesh another 
gear with this one; but when this one is rotating or spinning, it is 
not so easy, particularly for the novice. 



Fig. 265. Simple Device for Inserting Corks in Clutches 


Clutch spinning may be caused (1) by a defect in the design, 
in which case little can be done with it; (2) by a defect in construc¬ 
tion, as in balancing, for instance, which can be corrected; or (3) 
it may be due to external causes, as, for instance, in a bearing which 
has seized, owing to a lack of lubricant, etc. 

In any case, the best and quickest remedy is a form of clutch 
spinning brake. This may consist simply of a small pad of leather 
or of metal covered with leather so located on the frame members 
that the male drum touches against it when fully released. Or it 
may be something more elaborate as to size or construction or both. 
On many modern cars, in fact on practically all good cars, some form 
of clutch spinning brake is fitted. Thus, the Hele-Shaw design pro¬ 
vides at the left end, Fig. 256, a metal cone of small diameter, while 
Fig. 255 shows flat concentric discs 19 of the Locomobile clutch. 

Cork Inserts. When cork inserts are used in a clutch, the 
insertion of new corks is not an easy job. A cork is a difficult and 
unhandy thing to work with, and above all to hold straight and true 

























376 


GASOLINE AUTOMOBILES 


while applying longitudinal force to it. By making up a special 
tool with a tubular member having an inner taper, into which the 
corks are forced by means of a special plunger which forms the other 
part of the tool, this is simplified considerably. This tool is shown 
in Fig. 265, with such dimensions as would be needed for a J-inch 
cork. It is advisable to make the small end of the tube J inch smaller 
than the cork, as this amount provides the proper compression. 
After being soaked in water for 10 or 15 minutes, the cork is dropped 
into the large end of the tube, and, with the small end in place 

against the cork opening in the 
clutch, a single stroke of the plunger 
will force the cork through the tool, 
incidentally compressing it into the 
hole in the clutch. With a few 
handlings any clever mechanic can 
soon become expert in the use of 
this tool. 

A more elaborate device, but 
one which works more quickly where 
there is a great deal of this work, is 
shown in Fig. 266. This is not an 
expensive machine — the original of 
this sketch was home made. The 
framework is made of standard pipe 
fittings, the spring is a valve spring, 
and the rods are cold rolled steel. 
Only a few pieces such as the working 
member C were specially made. The 



Fig. 266. Machine for Handling Cork 
Inserts Quickly 

Courtesy of “Motor World ” 


working member is made with a slot 
at A into which the corks are inserted. 


When the pedal attached to the rod I) is pressed, it brings the rod 
down and forces out the cork at B. At point B, the clutch resting 
on the anvil E is held ready. The stop limits the downward move¬ 
ment, so a strong stroke of the foot will just push the cork into the 
hole flush and no more. The lower end of the working member is 
made with a taper so as to compress the corks about § inch, as men¬ 
tioned before. They should be soaked in water just the same as 
when using the hand tool. 



































GASOLINE AUTOMOBILES 


377 


In Fig. 267, several other common clutch troubles and their 
remedies are suggested; the parts shown in the illustration, however, 
are in excellent condition, in fact, new. 

W hen the right kind of clutch discs for a multiple-disc form are 
not on hand, new discs can be cut from leather to answer the purpose 
by means of the gasket cutter, shown in Fig. 268. This cutter con¬ 
sists of a pair of steel L-shaped arms, preferably forged, with points 
sharpened enough to cut the leather or the gasket material. The 
clamp has a point for the center of the circle on its under side, while 



Put on new limnd 

\ 

pBploceworn 


,Jlockp m slip joint 


should be sc|uare,trae 


Surfaced. 0* 'well oilecL 


Thesenots 


most 


tight ® well 
locked or 


for wear m universal 
joint bushings 

peplaoe all missing 


screws 


Fig. 267. Clutch Troubles Illustrated 

the actual clamping is done by the bolt or screw with wing head 
To use for clutch discs, set the inner, or shorter, member to the radius 
of the insole of the outer discs and the outer, or longer, arm to the 
radius of the outside of the inner discs. By pressing down hard on 
the arms and rotating them at the same time, an annular ring will 
be cut out which will fit exactly. One hand should be held on or 
near the center, while the other hand supplies the pressure and 
rotating motion on the cutting ends. It should not be expected that 
the points will cut through in one revolution; on the contrary, the 
first time around will just mark out the section and it will need from 








378 


GASOLINE AUTOMOBILES 


6 to 10 revolutions, with heavy pressure, to cut a leather disc. In 
time, the workman will become skilled in the use of this cutter and 



Fig. 268. Method of Cutting Facing for Disc Clutches in an Emergency 

Courtesy of “Motor World" 



have a knowledge of its limits, as well as of the method of keeping it 
in good cutting order. 

Adjusting Clutch Pedals. Some cars are made with adjustable 

* 

clutch pedals so the long- or short-legged driver can set the length of 
these to suit, but when no adjustment is provided and it is desired 
to change the length, some figuring must be done. To shorten a 
non-adjustable pedal, the best way is to take it out of the car and 

bend it somewhat on the order 
of the dotted lines in Fig. 269. 
The idea is to make the same 
amount of metal take a 
roundabout and longer path. 
In doing this, the workman 
must be governed largely by 
what the floor boards and the 
other parts of the mechanism 
in the immediate vicinity will 
allow. The bend must be 
made so as to allow the pedal 
to work in the same slot. If 
necessary, cut the slot a 
little longer, but first consider the result before bending the pedal. 

On the other hand, when the pedal is too short, the pad can be 
removed from where it is bolted on at A and a pair of steel strips 
cut so as to fit into the two sides of the pedal shank and brought 


Fig. 269. 


Schemes for Shortening or Lengthening 
Clutch Pedals to Fit Driver 






GASOLINE AUTOMOBILES 


379 


together at the other end. These are bolted in at A, where the pad 
was formerly, and the pad moved out to the new end at B. In some 
such cases, where the sides of the pedal shank offer no groove to help 
hold the steel strips, it is necessary to put another bolt through them, 
as at C, to prevent the whole addition swinging about A as a center. 

Clutch Troubles Outside of Clutch. Frequently, there is trouble 
in the clutch when the basic reason for it is outside of the clutch 
entirely. Thus, failure of a clutch to engage or disengage properly 
is often the fault of the connecting rods and levers; wear in the clutch 
collar or in other parts; or the emergency-brake interlock may have 
been fitted so close that as soon as the rods are shortened once or 
twice to compensate for wear, it stands in such a position as to throw 
the clutch out slightly although the latter appears to be fully engaged. 

Another clutch trouble outside of the clutch is apparent slipping 
at corners, especially at turns on grades. On a turn—the road being 
cambered—the frame is distorted, especially with the combination of 
curve and grade. This may be sufficient to throw the clutch and 
driving shaft out of alignment just enough so the clutch face will not 
make full contact. This is most noticeable on cars with a single 
universal joint, in which case the distortion of the frame has more 
effect on the driving shaft. Similarly, a car with an unusually light 
or flexible frame will show this trouble very often, as the combination 
of curve and grade is too much for the light frame. 

Summary of Clutch Troubles 

Throwing in Clutch. Do not throw clutch in suddenly and cause 
rear wheels to spin. Such action is destructive to tires and throws 
great stress on the entire mechanism of the car. 

Lubricating Multiple=Disc Clutches. These are best lubricated 
by injecting oil into the opening for that purpose by means of an oil 
gun. A very light lubricating oil should be used. 

Multiple=Disc Clutches Failing to Hold. Inject three or four 
gunfuls of kerosene into the clutch housing and run the engine a 
little, thereby washing out the plates of the clutch. This will cut 
the gum caused by the oil. If, after this treatment, the clutch 
squeaks or takes hold too suddenly, lubricating oil may be added. 

Loss of Power. This is noticeable in changing from intermediate 
to high gear, in climbing hills, or in running through muddy or sandy 


380 


GASOLINE AUTOMOBILES 


roads. The trouble is often the result of the clutch slipping. The 
remedy is to clean the clutch with gasoline and, if the clutch is leather- 
faced, to apply castor oil after cleaning. Castor oil should never be 
used on the multiple-disc clutch. 

Failure of Clutch to Take Hold. This may be owing to a broken 
or weakened clutch spring, the clutch leather may be damaged, 
clutch shaft may be out of line or bent, leather may be gummed, 
or bearing may be seizing. 

TRANSMISSION GROUP 

Primarily, the clutch is used to allow the use of change-speed 
gearing; or, stated in the reverse way, the form of the transmission 
determines whether a clutch must be used or not, there being cases in 
which it is not used. Thus, where the frictional form of transmission 
is used, no clutch is necessary; the frictional discs act as a clutch 
and render another one superfluous. So, too, with the form of trans¬ 
mission known as the planetary gear, no master clutch is needed. 

On the other hand, the reverse of this does not always hold. Anv 
form of clutch may be used with the various other forms of transmis¬ 
sion, as the sliding gear; in fact, in actual practice every known kind 
of a clutch will be found coupled with the sliding-gear transmission. 

Classification. Broadly considered, there are five classes of 
transmissions used. In cases where the use of any one of these 
forms eliminates the final drive, this from its very nature does not 
alter the facts but simply calls for a different and more detailed 
treatment. The five classes are: 

/ Operated in various ways 
l but usually selective 

(2) Individual clutch 

(3) Planetary, or epicyclic 

(4) Friction disc (various arrangements) 

(5) Miscellaneous 

The features of the 1917 transmissions which stand out from 
previous years are: reduced sizes; simpler, lighter construction; 
greater compactness and greater accessibility. Perhaps the most 
noticeable trend has been toward the unit power plant which has 
helped materially to make transmissions smaller, lighter in weight, 
and more simple, with unusual compactness. This very compact- 


(1) Sliding gear 


GASOLINE AUTOMOBILES 


381 


ness has brought with it a stiffness which has rendered less repairs 
and adjustments necessary, despite lighter weight. The smaller sizes 
have brought about the simplification and lighter weight, and in 
turn have been produced in answer to the popular demand for lighter 
weight cars. In part, simplification has been produced by unit 
power plants, now so popular. 

SLIDING GEARS 

General Method of Operation. Of the different types of sliding 
gears, the first two subdivisions are not very closely marked, but 
blend somewhat into one another. The only real difference between 
them is the method of operation, the names serving to indicate the 
distinctive characteristics. Thus, in a selective gearset, it is possible 
to “select” any one speed and change directly into it without going 
through any other. So, too, in the progressive form of transmission, 
the act of changing gears is a “progressive” one, from the lowest up 
to the highest, and vice versa. 

Selective Type. With the selective method of changing gears, 
it is possible to make the change at once from any particular gear 
to the desired gear without passing through any other. Of course, 
the car will not start on the high gear any more than in the other 
case, but shifting into low for starting purposes is but a single action, 
accomplished quicker than it can be told. So, too, when the car has 
been started, it can be allowed to attain quite a fair speed and the 
change to high made at once without going through the intermediate 
gears. 

Progressive Type. Progressive gears, which are now little used, 
operate progressively: from first, or low, to second and from second 
to third, or high; in slowing down, from third to second to first 
and in this way only. This leads to a number of troublesome 
occurrences; thus, in stopping, it is necessary to gear down through 
all the higher speeds into low. If this is not done, when it is next 
desired to start the car, it will be necessary to start the engine, throw 
in the clutch, drop from the gear in mesh to the next lower, from that 
to the next, and so on down to low, throwing the clutch out and in 
for each change of speed. When first is reached, the car may be 
started. After starting, it is then necessary, in order to obtain any 
measurable speed with the car, to change back up the list, from low 


382 


GASOLINE AUTOMOBILES 



Fig. 270. Cadillac Transmission and Housing 

shaft, which formerly was on the same horizontal level as the main 
shaft, is now placed directly below it. This makes a higher but 
narrower gear box, that is, instead of being wide and fairly flat, it 
is now high and narrow. The placing of the shifting levers on the 
cover, directly over the center, has aided in making the gearset more 
compact than formerly. In it there are two shifting gears, one gear 
carrying a set of dogs cut into its face, which mesh with a similar set 
on the main driving gear to give the direct drive. The gear portion 
of this member meshes with another gear for second. The second 
shifting member meshes with one gear on the layshaft for low speed 


to second, from second to third, and so forth. In this way the pro¬ 
gressive gear is disadvantageous, since its use means much gear 
shifting; but, on the other hand, the shifting is very easy for the 
novice to learn, as it is a continuous process, all in one direction. 

Modern Selective Types. To present some modern selective 
types of gear boxes and point out their various differences, advan¬ 
tages, and disadvantages, refer to Fig. 270. This type shows the 
three-speed selective gear used on the Cadillac cars, which is but 
slightly modified from the type which has been used by this concern 
for three years. This change should be noted, however; the lay- 










GASOLINE AUTOMOBILES 


383 


and with another on the third shaft for reverse. The reverse gear 
is at all times in mesh with the fourth layshaft gear, so that on 
reverse the drive is through five gears instead of four. On high gear 
the drive is through the dogs, the layshaft being driven, of course, 
but silently, as it transmits no power. 

Four-Speed Type with Direct Drive on High. One of the tend¬ 
encies of recent years has been the gradual change toward more 
speeds, as shown by the increasing use of four-speed gear boxes. 



Fig. 271. Sectional Plan Drawing of the Locomobile Four-Speed Transmission 
Courtesy of Locomobile Company of America, Bridgeport, Connecticut 


Other indications of this change have been the two-speed axle, which 
gave double the number of gear-box speeds, with the ordinary three- 
speed and reverse transmission; and the electric transmission, which 
affords seven forward and two reverse speeds. 

Following this increase of speeds, the multi-cylinder motors and 
downward price revisions of the early part of 1916 brought about a 
combination which almost eliminated the four-speed gear box or at 
least removed it from all but the most expensive of cars and from 




































































































































































































384 


GASOLINE AUTOMOBILES 


many of those. It is claimed that the eight- and twelve-cylinder 
motors have so much power and flexibility that a fourth speed is 
rendered unnecessary. The four-speed gear box is more expensive 
than the three-speed box, and the lowered prices of cars have been 
instrumental in preventing its continued use. At the same time, 
there was considerable lightening of weight all over the chassis, and 
the four-speed gear box had to go out of all but the biggest cars on 
account of its greater weight. 

Fig. 271 is a sectional plan of one of the few four-speed gear 
boxes left. In this drawing it will be noted that the two-gear shafts, 
as well as the operating shafts, lie in the same horizontal plane. The 
halftone reproduction of the photograph of this drawing, Fig. 272, 



Fig. 272. Photographic Reproduction of Locomobile Gear Box Shown 

in Section in Fig. 271 


shows the location of the shafts even more plainly and will, perhaps, 
be of more use to the average reader. Both forms show the arms 
which project up ta attach this unit to the frame. The cover, which 
is a light easily removed aluminum member, is taken off from above 
after the floor boards are lifted out. This arrangement makes for acces¬ 
sibility and eliminates any need for lying on the ground while working 
on the transmission gears or shafts, should such work be necessary. 

The form of final drive alters the construction of the trans¬ 
mission very materially. Formerly, when all final drives were of the 
double-chain form, it was customary to include the differential, 
bevel gears, and driving shafts in the gear box. Now that the chain 
has gone out, this construction is found only when the gear box is a 
unit with the rear axle. 



GASOLINE AUTOMOBILES 


385 


h our-Speed Type with Direct Drive on Third. In all the trans¬ 
missions shown and described thus far, the direct drive has been 
the highest speed. By referring back to Fig. 253, which show the 
Winton four-speed gear box, as well as the clutch, a point of difference 
will be seen. This has the direct drive on third speed, fourth being a 
geared-up speed for use only in emergencies, when the very highest 
rate of travel is required, and when a little noise more or less would 
make no difference. This arrangement of the direct drive and silent 
speed has long been a debated point, some designers favoring the 
direct-drive type with an over-geared speed for occasional use, while 
the opponents of this method say that this construction practically 
reduces the transmission to a three-speed basis, the fourth being so 
seldom used that it is practically negligible. They say, also, that the 
modern motor can attain a high enough speed, on the one hand, and is 
flexible enough, on the other, to permit its being used with the high- 
gear direct drive upon almost all occasions. 

Transmission Location. There are but four recognized positions 
for the transmission in the modern car. These are: (1) unit with the 
engine (unit power plant), (2) amidships in unit with clutch or alone 
in a forward position, (3) amidships in unit with forward end driving 
shaft or in a rear position, and (4) at the rear in unit with rear axle. 

Unit with Engine. The unit with the engine type is illustrated in 
an excellent manner in Fig. 273, which shows the eight-cylinder 
Northway motor, cone clutch, and three-speed transmission. Some 
idea of the compactness of this outfit, which is shown exactly as used on 
the Oakland car, can be gained from comparison with cylinder bore 
and crankshaft size, the motor being 3J by 4§ inches. The notice¬ 
able features of the transmission, aside from its compactness, are the 
use of double row ball bearings on the splined main shaft, with a 
Hyatt roller form for the spigot bearing (free end of main shaft) and 
very long plain bronze bushing for the countershaft unit, the latter 
being made as a single piece rotating on a single bearing around a 
straight fixed shaft. The countershaft, or layshaft, as it is some¬ 
times called, is placed below the main shaft. 

Another example of the unit with engine type is seen in the 
Grant-Lee three-speed gear box, Fig. 274, as utilized in the Hackett 
car. This is unusually small and compact, as will be noted by com¬ 
paring the size of the unit with the operating levers and pedal. While 


386 


GASOLINE AUTOMOBILES 



Fig. 273. Unit Power Plant of Oakland Eight-Cylinder Car 
Courtesy of Oakland Motor Car Company, Pontiac, Michigan 











































































































































































































































































































































































































GASOLINE AUTOMOBILES 


387 


the clutch is not shown, its housing is, also the flange which attaches 
it to the flywheel housing to complete the power unit. A third 
example of the engine-unit power group is shown in Fig. 275, which 
shows the flywheel, clutch, and transmission of the Peerless eight. 
This unit transmits many times the power of the Hackett unit and 


In this unit the bearing arrangement is 


is therefore much larger, 
rather unusual, as roller 
bearings of the taper form 
are used on the main shaft, 
a straight roller for the 
spigot bearing, and plain 
ball bearings for the lay- 
shaft. The shortness and 
large diameter of the 
shafts should be noted. 

Additional transmis¬ 
sions in a unit with clutch 
and motor will be seen 
under Clutches, in Figs. 

251,252, and 254. 

Amidships Alone or 
with Clutch. The amid¬ 
ships unit joined with the 
clutch, shown in Fig. 253, 
represents the Winton 
transmission and clutch. 

This is not a common con¬ 
struction on pleasure cars, 
although it is used on 
quite a number of trucks. 

On the amidships-clutch 
unit type, however, the 
combination is not quite so 
intimate as the one in which the two units are enclosed in a common case. 

Amidships Joined with Driving Shaft. The amidships unit 
joined with the forward end of the driving shaft is well shown by the 
Locomobile, Figs. 271 and 272. The universal joint with the driving- 
shaft pivots is seen at the left side of both these views. In this 



Fig. 274. 


Gear Box Used in Hackett Cars Is Very 
Small and Compact 

Courtesy of Hackett Motor Car Company, 
Jackson, Michigan 







































388 


GASOLINE AUTOMOBILES 


construction, which is more widely used than the other amidships 
arrangement, there is usually a frame cross-member at the point on 
which the rear end of the transmission is supported. This same 
arrangement is used on the Stearns-Knight four-cylinder chassis, the 
transmission of which is shown in Eig. 276. In this transmission 
the stiffness of the cross-member at the rear end of the transmission 
is also utilized to support the brake drum of the foot-brake system. 



Fig. 275. Gear Box and Clutch of Peerless Eight 
Courtesy of Peerless Motor Car Company, Cleveland 


The short stiff shafts on the transmission will be noted, also the many 
splines on the main shaft and the use of double row ball bearings on 
the main shaft, with a flexible roller on the spigot, and the same type 
of bearings on either end of the layshaft, which is alongside of the main 
shaft. Note also the means provided for adjusting the countershaft 
longitudinally by the two steel screws projecting through the bear¬ 
ing caps so that this adjustment can be made from the outside. 














































































































GASOLINE AUTOMOBILES 


389 


Rear Unit with Rear Axle. The position at the rear axle is 
not as widely used as a couple of years ago, but those manufacturers 
using it have large outputs, so that a considerable number of these 
cars are in use and considerably more are being added each year. 
One of these, the Studebaker, is shown in Fig. 277. This is a shadow 
drawing of the rear axle and transmission, showing the upper, or 
main, shaft of the transmission in full and the layshaft which is below 



Fig. 270. Three-Speed Transmission and Brake of Stearns Four-Cylinder Car 
Courtesy of F. B. Stearns Company, Cleveland, Ohio 


it, partially. As will be noted, this position of the transmission 
calls for two operating rods, each the full length from the operating 
levers to the rear axle. The rod on the left operates the reverse 
and first speeds and that on the right second and third, or high, speeds. 

To make this shifting of gears and connection of levers with 
the actual position of the gears plain, Fig. 278 is also shown. In 
this figure the gear-shifting lever is placed in the center and is shown 
solid in the neutral position and lighter in the other four positions. 


























































































































































GASOLINE AUTOMOBILES 


390 



Just below it, the transmission is shown with the position of the 
gears for neutral, while in the four corners, corresponding to the four 
positions of the lever, the positions of the gears when the lever 
is in each one of the positions are shown. These positions indicate 
that there is a driving gear and two sliding 
members on the main shaft and four gears 
on the lay shaft. At the left in the picture, 
the gear toward the rear is for reverse and 
another gear (not shown) is needed to com¬ 
plete the reversal of motion. When the 
lever is swung to the left and forward, this 
group is completed and reverse speed 
results. 

When the lever is swung to the left 
and pulled backwards, the rear sliding 


Fig. 277. Studebaker Transmission Combined with Rear Axle 
Courtesy of Studebaker Corporation, Detroit, Michigan 


member is moved forward to mesh with the second gear on the lay- 
shaft, as shown in the diagram at the lower left-hand corner, and first, 
or low, speed results. With this gear in its neutral position—as it 
is left when the shifting lever is swung through the neutral position 















































GASOLINE AUTOMOBILES 


391 


and over to the right—a further movement to the front picks up the 
forward sliding gear and moves it back into mesh with the third gear 
on the lay shaft; this combination, as shown in the upper right-hand 
corner, gives second speed. When the lever is moved back, it moves 



REAR AXLE 


FRONT OF CAR 


REAR AXLE FRONT OF CAR 


— 



SECOND SPEED 

HIGH AND INTERMEDIATE 
SLIDING GEAR 

JAWS 

MAIN DRIVE PINION 

I 

T GEAR 


REVERSE 

MAIN DRIVE OR 
TRANSMISSION SHAFT 


I OW AND REVERSE 
SLIDING GEAR 


INTERMEDIATE 
counttrsm vet gear 


REVERSE IDLER 


LOW SPEE 
COUNTEKSHAF I GEA 


/ 


REVERSE 
C'OUNTE I’SHAt I GEAR 





Fig. 278. Diagrams Showing Working of Studebaker Transmission 


the gear forward, giving high speed and direct drive, as shown at the 
lower right-hand corner. 

Interlocking Devices. Nearly all transmissions have a form of 
stop lock on the shifting rods in the transmission, which holds the 
gears in mesh as soon as they have been moved by the operator 
until he moves them again. In reality this arrangement simply 
prevents the gears from jumping out of mesh. Generally, the most 
simple arrangement which will hold the gears is used. In the ordinary 















392 


GASOLINE AUTOMOBILES 


form this arrangement consists of hardened steel wedges with light 
springs back of them and deep grooves in the shifting rods into which 
these wedges fit. 

In Figs. 271 and 272, the notches in the shifting rods can be 
seen plainly. In Fig. 275, the bolt head A indicates the location 
of one of the shifting locks. In Fig. 277, A shows the notches in 





Fig. 279. Various Forms of Transmission Interlocks 


the low and reverse rod and B those on the second and high-speed 
shifting rod. 

Not all transmissions have the wedge and notch, as Fig. 279 
indicates. This figure shows: at A, a method of interlocking by 
means of a pin at the shifting forks (not rods) which project into 
shallow holes in the two shifters; at B, a rocking, or tilting, bar 
beneath the shifting forks, which is pressed into a notch in either 
fork when moved from neutral; and at C, the use of a steel ball—all 
three arrangements being used by the American Die and Tool 
Company. The form at D shows the pin used by Grant-Lee Gear 




























































GASOLINE AUTOMOBILES 


393 


(Company, the grooves in the rods being deep enough to accommodate 
this form in a neutral position so that the rod can be started. But the 
guide hole in the central housing in which the pin is moved across by 
the motion of one rod, owing to the shape of the bottom of the groove, 
prevents the other rod from moving. 

Electrically Operated Gears. In substance, the electrically 
operated transmission has all the hand levers, rods, and other levers 
replaced by a series of push buttons. When it is desired to change 
speeds, even before the actual change is necessary, the driver presses 
the button marked for the speed he thinks he will require. Then, 
when the actual need becomes apparent, he throws out the clutch 
and immediately drops it back again, all this forming but a single 
forward and back movement of the 
foot. During the slight interval while 
the clutch is out, the electrical connec¬ 
tions shift the gears automatically, so 
that when the clutch is let back, the 
gears are meshed ready to drive. 

Principle of Action. To explain 
this action briefly, the gears are moved 
by means of solenoid magnets, which 
are nothing more than coils of wire, 
through which an electric current from 
a convenient battery is allowed to pass. 

Through the center of each one of these 
coils passes an iron bar. When a cur¬ 
rent passes through the coil, it is con¬ 
verted into an electromagnet and draws,the iron bar inward. As the 
other end of the bar is connected to the gear to be shifted, this move¬ 
ment of the bar shifts the gear. Consequently, when the button is 
pressed so that current flows through one of the coils, that action 
shifts the gear for which the button is marked. 

By referring to Fig. 280, this action will be made more clear. 
The diagram shows but one pair of gears to be meshed, and the 
battery, push button S, coil D, iron bar P, and clutch connection 
M are all shown as simply as possible. When button S is pressed, 
current through the coil D will, draw the bar P and mesh the 
gears as soon as the clutch has been thrown out, thereby closing 



Fig. 280. Sketch Showing How a 
Solenoid Moves a Gear When 
Current Flows 
































394 


GASOLINE AUTOMOBILES 


the circuit at M. The application of this to an actual transmission 
is shown more in detail in Fig. 28], which shows the clutch pedal 



Fig. 281. Arrangement of the Solenoids and Pedal in the C-H Electric Gear Shift 


and its connection to the six solenoids necessary to produce four 
forward speeds, one reverse speed, and a neutral point. 

On the steering wheel, Fig. 282, the control group cf six buttons 
will be noted on the small round plate at the center, with the addition 
of the horn button in the center. In Fig. 283 is another arrangement. 

In the 1916 forms of electric-control systems, the buttons are 
grouped in one instance on the top of a small box four or five inches 



Fig. 282. Arrangement of Buttons Fig. 283. Another Arrangement of Buttons 

for Gear Shifting for Gear Shifting 


square, which is placed on the steering post below the wheel; in 
another, on the dash; and in a third, on a rod connecting post and dash. 











































































































































GASOLINE AUTOMOBILES 


395 


Pneumatic Shifting System. The pneumatic system of gear 
shifting is along lines somewhat similar to the electric system, air 
under pressure being used to move the gears instead of a hand lever 
and rod combination. For this purpose it is necessary to add an 
air compressor, a tank to carry the compressed air, and what is 
called the “shift”—really a complicated valve and a series of plungers 
—to the car. The valve and plungers respond to a finger lever on the 
steering wheel, the same as the electric system responds to the but¬ 
tons. Air is admitted behind the plungers, which moves the gears 
as soon as the clutch is depressed. It is seen, therefore, that this 
system, like the electric shifter, permits the anticipation of the 
needs of the car. 

Railway Car Needs. All transmissions previously presented 
have had but one reverse. For gasoline railway cars, the inability 
to turn the car requires as many reverse speeds as forward, which 
means special gearing. Usually, this gearing is accomplished by 
means of a pair of bevels, each with a clutch, meshing with a single 
driving bevel. Obviously the two driven bevels will turn in different 
directions, and each will drive when its clutch is engaged. By 
shifting the clutch to the one which gives a forward speed, all the 
speeds of the gear box become forward speeds; by shifting to the one 
which gives reverse, all the speeds become reverse speeds. 

INDIVIDUAL CLUTCH 

General Types Used. While the number of adherents to the 
individual-clutch type of transmission is not as great as that of either 
the progressive or selective types of sliding gear, it holds its own; 
and, as time passes, it gains adherents. In this form, all the gears 
are in mesh at all times, and what has been called “the barbarous 
and unmechanical” method of clashing gears is entirely done away 
with. The individual-clutch type is operated on the selective plan 
but otherwise has nothing in common with the latter. 

The forms of clutches used vary greatly, as might be expected. 
The following are in use today: jaw clutches (both two- and 
multiple-jaw); internal-external gears, multiple disc, cone, and 
friction clutches other than the multiple-disc form. 

Using Internal Dogs . One type in which the gears are engaged 
by internal dogs—the gears being in mesh at all times—has four sets 


GASOLINE AUTOMOBILES 


396 

of gears, those on the main shaft being keyed or otherwise fixed to 
the shaft, while the gears on the jackshaft run idle except when the 
gear-shifting lever is moved forward to an engaging position, which 
throws an internal dog up into a slot inside the gear. T his position 
makes the gear one with the shaft, and the power is transmitted 
directly. The dogs in the latest form of this transmission take the 
form of hardened and ground steel balls. 

Disc Type . Many of the early individual clutch types of trans¬ 
missions used discs, each gear having its own set and each set having 
sufficient surface to carry the whole power of the motor. While 
bulky, this had undeniable advantages, for it allowed starting on 
any gear. 

Contracting-Band Type. While advocates of discs are numerous, 
other devices do not lack friends. Fig. 284 shows a form on the 

H aynes-Apperson 
cars that attained much 
popularity. In it the 
clutching action is pro¬ 
duced by means of con- 
tracting bands working 
on large diameter drums, 
z the drums being keyed 
each to its own gear. The 
full explanation of the 

Fig. 284. Early Form of Haynes Clutch Gearset action ig ag f o H 0ws ; The 

engine drives the shaft A, upon which are mounted the gears C, D, E, 
and F. These are all permanently fixed to the shaft and rotate with 
it. Upon the driven shaft B are mounted an equal number of gears 
meshing with the former, but all loose upon the shaft so as to spin idly. 
Bolted to each of the latter gears is a large drum, while close to it is a 
framing upon which is mounted a contracting band. The latter fram¬ 
ing is keyed to the shaft, so that when it is rotated the shaft must 
turn with it. In action, then, when any speed was desired, the band 
was contracted until it seized the drum bolted to the gear which gave 
that speed; thereupon, the gear, drum band, and framing all turned as 
a single piece. 

Smyle-Disc Winton. Winton long advocated the individual 
clutch gear, his clutch taking the form of a single disc pressed 


















































































































GASOLINE AUTOMOBILES 


397 


against the gear by means of numerous fingers, Fig. 285. A conical 
sliding piece G or J expanded the fingers pivoted on M and II so that 
they pressed against the 
disc within the gears D, 

K, or N. 

Internal-External Gear 
Type. Many of the gears 
already given date back 
several years, but the 
gear illustrated in Fig. 

286 is more modern, 
and is being used today 
b y the International 

Motor Company of New York City and of Allentown, Pennsylvania. 

_ % 

The principle upon which this gear works, as shown by Fig. 286, 
is that of the internal-external gear. The gears which transmit the 
power are always in mesh. Each one of these is bushed and runs idly 
upon the main shaft. Contained within each gear and an integral 
part of it is an internal gear of twenty-four teeth. Sliding on the 



Fig. 285. Early Form of Winton Individual 
Clutch Transmission 



Fig. 286. Mack Commercial Car Individual Clutch Type of Gear Box 
Courtesy of International Motor Company, New York City and Allentown, Pennsylvania 


squared shaft are four 24-tooth gears; these are specially built for easy 
engaging with the internally cut gears. 

To follow the letters placed on the parts of this gear, high speed 




















































































































































































































































































































398 


GASOLINE AUTOMOBILES 


is obtained by sliding the piece 2-C-31 forward into gear 2-C-34; 
this action swings the piece, shown dotted beneath, so as to throw 
out the clutch on the lay shaft 2-C-52. On high speed, the two gears 
locked together are the only ones to turn, all others being idle. The 
same piece 2-C-31, when slid to the right, meshes with the internal 
gear of the second-speed pinion 2-C-160. This sliding member slides 
upon a squared shaft, so the drive is positive. The action of the first, 
or slow speed, and reverse are the same as those just described, being 
produced by the shifting of the clutch member 2-C-66. Attention is 
called to the ball bearings used on this transmission, which are 
remarkable only when it is remembered that this is a commercial truck 
transmission. Students of automobile construction will find many 
interesting constructional details in this illustration, which is a repro¬ 
duction of the manufacturer’s working drawing. 

Still another similar form uses three cone clutches in the trans¬ 
mission, that for the high speed being augmented by a set of pins, 
or dogs, which, as the clutch gradually takes hold, slip into an equal 
number of holes in the driven gear. In this way, the two are made 
as one, which makes slipping impossible—a very important feature. 

Transmission Operation. As has been pointed out previously, 
practically all transmissions operate all gears by means of a long hand 
lever, placed either at the side of the car or in the center, according 
to the location of the control. Even on planetary forms, still to be 
described, at least one of the various speeds is controlled by a hand 
lever. The electric- and air-shifting methods have made a start, and 
a good one, but until their number increases materially, these types 
can be considered as only having started their development. 

Transmission Lubrication. A fairly heavy lubricant is gener¬ 
ally recommended for gear-box use—either a special form of about the 
right consistency, or else a home-made mixture of about half-and- 
half of light oil and hard grease. Some firms recommend a graphite 
grease. The lower part of the case should be filled to a point, or 
level, where the largest gears dip continuously. This will insure a 
constant agitation of the lubricant, which will thus get to all moving 
parts and surfaces. Having the lubricant too stiff is bad, because then 
the gears simply cut a path through it without moving the rest. 
This results in all other parts running practically dry. Too thin a 
lubricant or too much of it will make a fairly heavy drag on the motor, 


GASOLINE AUTOMOBILES 


399 


which loss of power should be avoided. Gear-box lubricant generally 
is introduced in bulk by the removal of the cover, usually of a large size 
to allow of this. The outside parts carry their own grease and on cups. 

Transmission Bearings. By looking back at the various trans¬ 
missions shown, it will be noted that ball bearings are used most 
freely. Roller bearings in various forms are coming into use, as the 
shorter series produced in the last couple of years has shown 
designers that thist ype would produce a compact gear box, their size 
having previously limited their use. Plain bearings are not used at 
all on good cars. 

Transmission Adjustments. Few adjustments are needed in 
the modern gear box. However, provision for wear is made in the 
operating rods and levers, both within the case and without. In 
some cases the shafts may be slightly shifted endwise to secure 
better meshing of the gears after wear. Bearings, too, are arranged 
to shift slightly in an endwise direction to take care of wear in other 
parts and not so much in the bearings themselves. 

PLANETARY GEARS 

Method of Action. The planetary, or epicvclic, form of gear¬ 
ing offers many advantages, but, strange to say, the American 
people, although inclined toward simplicity and cheapness in com¬ 
bination, will not have it in this form, and, as a consequence, this 
excellent gear-reducing means is fast losing favor. The principle 
upon which all planetaries work is as follows: Connected to the 
engine is the first gear of the train. The second is one of a series of 
several gears; these are pivoted in a drum, which may be held station¬ 
ary by a brake band. The middle, or third, gear in the train, as well 
as the last, or fourth, is connected to another gear, a driven gear, not a 
driver. Considering but a single rotating train—there usually are 
three or more—the last-named gears form the fifth and sixth in the 
whole train. Gears two, three, and four have different numbers of 
teeth, as well as gears one, five, and six. Holding the band which 
holds the drum to which the gears are pivoted, allows each of them 
to rotate around its own axis, but not around the main shaft. This 
form of rotation gives one gear reduction. 

Another band holds another gear stationary and allows the 
three-gear unit to rotate around the main shaft as an axis; at the 


400 


GASOLINE AUTOMOBILES 


same time it leaves them free to also rotate around their own axis. 
This produces another gear reduction. Another form which is 
popular in so far as planetary gears are popular is that in which 
internal gears are substituted for one set of the planets, from which 
the device obtained its name. This does not complicate the device 
any; in fact, the only way in which it makes any change is in the 



manufacturing cost of the gear, internals costing more than spur 
gears. 

Ford Planetary Type. Ford has been a consistent user of the 
planetary gear; in fact, the simplicity and ease of operation of his 
well-known and widely used car is largely due to this use. The Ford 
transmission, which is of the all-spur-gear type, is shown in Fig. 287. 
This is operated by means of two pedals and a lever, one pedal 
working high and low speeds, while the other pedal controls the 
reverse. The first-named pedal, however, must be used in conjunc¬ 
tion with the forward movement of the hand lever which locks the 
high-speed clutch, seen in this figure at the right. 






























































































































































































GASOLINE AUTOMOBILES 


401 


FRICTION DISC 

Undoubtedly, when simplicity is sought regardless of cost, the 
friction drive is the drive used. The cost with this form is not one 
of money, but rather of other things which must be sacrificed if 
friction drive is used. 

Spur Type. In the interest of simplicity, it may be said that 
the friction form of drive dispenses with the clutch, being of itself 
both clutch and change-speed gear. The usual form which this takes 
is the single spur wheel contacting with another flat-face wheel. 
Since these must be at right angles, the car is nearly always chain 
driven, the driving wheel 
being on the rear end of 
the crankshaft, and the 
driven shaft across the 
middle of the car. To 
secure a more certain 
drive and at the same 
time obtain the differ-. 
ential action, the cross- 
shaft, mounted upon two 
independent shafts, is 
often fitted with a pair 
of wheels, contacting 
with opposite sides of 
the driver. As this 
method causes the two 
driven shafts to turn in 
opposite directions, a gear is necessary at the end of one of them. 

The greatest feature of the friction drive is the multiplicity of 
speeds obtainable, these being infinite in number, since every dif¬ 
ferent position of the driven wheel on the driver results in a different 
ratio and, consequently, a different speed. To obtain these various 
changes, the wheel which meets the other edge-on is usually arranged 
to be advanced up to and withdrawn from the wheel presenting the 
Hat surface. In action, a motion of translation is given to the wheel 
at the same time as the motion up to or away from the surface. This 
motion of translation changes its position and consequently its 
speed. 







































































































402 


GASOLINE AUTOMOBILES 


Over the three-wheel arrangement, the use of the four-wheel 
arrangement possesses some undeniable advantages, particularly if 
the two parallel driving wheels are arranged to drive the others in 
pairs. This arrangement makes the direction of rotation of the 
wheels alike, and no intermediate gear to change the direction of one 
shaft is needed. A simplification of this form utilizes the flywheel of 
the engine as the forward driving disc. 

Bevel Type. Bevels have many advantages over spur friction 
wheels. They are found in combinations, such as a single pair of 
bevels or three bevels, and in multiple combinations, without limit to 
the number of bevels. Fig. 288 shows the use of a single pair, but 
in combination with a fiat face on one and a spur attached to the 
other; this makes the whole consist of four wheels in reality. 

Another combination sometimes used is that of three bevels. 
One of the bevels has a flat face and a spur, making really five wheels. 
The spur wheel in every case takes the final drive. A direct drive 
on the high gear is obtained by the use of a cone clutch on this spur 
and another clutch with which it engages on the driving wheel. One 
bevel gives forward speeds, and through the other the various reverses 
are gained. The friction drive, although theoretically the simplest 
and most ideal form of drive, is not very popular. 

MISCELLANEOUS TYPES 

Freak Drives. What are termed the freak drives attract much 
attention from inventors, but little from hard-headed constructors. 
Thus, the belt drive was once advanced as the simple drive, yet it 
made no progress. Today there are few belt drives used in final 
driving in America, although a few are still made in Europe. There 
is a low-price French car, Fouillaron, with this drive; and a single¬ 
cylinder Italian car, the Otav, selling for the equivalent of $150, 
which is also equipped with a belt drive. 

Cable and Rope Drives. When cycle cars were first brought 
out and by many considered as destined to replace both the low- 
priced cars, on account of their still lower price and simplicity; and 
motorcycles, because of their greater comfort, superior appearance, 
end greater carrying capacity, many of the simple drives were 
revived and applied to the cycle cars. The types used include the 
cable drive, which attracted much attention at one time in the motor- 


GASOLINE AUTOMOBILES 


403 


buggy field, the rope drive, the flat belt, the V-belt, the cloth-covered 
chain, and many others. With the collapse of the cycle-car boom, 
these went out of use. 

Hydraulic Gear. Janney-Williams . The hydraulic transmis¬ 
sion has been advanced as a cure for all automobile troubles, rep¬ 
resenting as it does the elimination of clutch, differential, and the 
driving mechanism. It consists of a pump to circulate the fluid, and 
one or two motors, usually attached to the rear wheels and propelled 
by the fluid. In the Janney-Williams hydraulic gear, which has 
successfully used fox some time in other fields, but has just 
recently been tried for automobiles in England, thei’e are three 
similar pumps, one being used as a pump and the other two as motors. 
By rotating the driving ring so that it assumes different angular 
positions, the throw of the small pistons, of which there are nine in 
all, is varied from zero up to a maximum. Since the action of the 
fluid in the motors connected to the wheels is opposite to this, it 
amounts to varying the speed, the number of changes being infinite, 
as in friction gearing. 

Manly. Another hydraulic drive, of equal merit and of Ameri¬ 
can manufacture, is the Manly. This differs from the Janney- 
Williams only in the form of the motors; the fluid and its use are the 
same in both cases. This drive has for its object the securing of any 
desired speed of the driven shaft, either foi*ward or backward, with¬ 
out changing the speed or direction of motion of the driving shaft 
and of transmitting the power to a shaft, which is either in line with 
the driving shaft or which lies at any angle to the driving shaft and 
is sepai’ated from it. It consists of a multi-cylinder pump having a 
variable stroke, which is attached to the driving shaft, and of one or 
more multi-cylinder motors having a fixed sti’oke, which are attached 
to the driven shaft, together with pipe connections, or passages, 
between them for transmitting the working field. The various 
cylinders, both of the pump and motors, radiate equidistantly from 
a central crank chamber, and the pistons or plungers are connected 
to a single crankpin which is common to all. The fluid used is 
ordinary machine oil, its lubricating qualities and freedom from the 
danger of freezing admirably fitting it for such a purpose. When the 
system is once filled, the oil is used over and over again, being in con¬ 
tinuous circulation from pump to motor through one set of pipes, or 


404 


GASOLINE AUTOMOBILES 


passages, and back again from motor to pump through another set. 
The stroke of the pump may be varied at will, but that of the motor 
is fixed. The variation of the pump stroke is accomplished by a 
crank, on which an eccentric bushing is mounted. By revolving the 
bushing with reference to the crank, its center line is brought into 
alignment with the center of the shaft, and when this position is 
reached, no reciprocating motion is communicated to the pump 
plungers. The Manly is constructed under license by the American- 
La France Fire Engine Company, Elmira, New York, and has proved 
its worth on very large trucks and on some of their fire apparatus. 

In recent years a number of hydraulic transmissions have been 
brought out, but all these face the fundamental difficulty that when 
the pump chamber is liquid tight the friction is excessive. 

Pneumatic Drive. There has been some talk of a pneumatic 
drive also, this idea not differing greatly from the previous one of 
using liquids. In this scheme a large tank of compressed air is 
provided for the purpose of starting the engine, helping to get up 
speed quickly, and for use on hills when excess power is needful 
or at least helpful. If used as planned, it would allow of the elim¬ 
ination of the reverse and would be utilized for braking as well, 
the present form of band brakes being replaced by air brakes. This 
is but a prospective scheme, never having been tried; yet in consider¬ 
ing the future, it is worth more than a passing thought because of 
its latent possibilities. 

Electric Drive. To speak of an electric drive sounds peculiar, 
yet that is what should be used for a final drive through the medium 
of electric motors. This form, spoken of abroad as the petrol-electric 
car, is attaining much headway there. It gains slowly, it is true, 
but, nevertheless, surely—each year seeing one or more makes 
added to the already long list of successful cars in this category. 

In the petrol-electric cars, the generator is coupled to the engine 
in the place ordinarily occupied by the flywheel and clutch, and the 
armature acts as a flywheel. Then the two motors are set on each 
side, directly in front of the rear wheels, which they drive through 
the medium of spur gears; the whole is enclosed to keep out dirt, 
keep in oil, and reduce noise to a minimum. 

On the whole, the electric drive is not losing ground, which, in 
these days of gasoline shaft-driven cars, is perhaps something gained. 


GASOLINE AUTOMOBILES 


405 


In fact, it might be said that the electric drive possesses so many 
advantages which are worth having, even at a sacrifice, and so few 
disadvantages that one is safe in figuring that a few more years 
will see the number of these drives doubled and possibly trebled. 

Electric Transmissions. While the drives just discussed might 
be called electric drives and still be precise, the Owen magnetic car, 
which is constructed by the Baker, Rauch and Lang Company, 
makes use of an actual electric transmission, the Entz, at one time 
used in a Columbia chassis. This is so arranged that all speed 
changing is done by a small finger lever on the steering wheel, similar 
to the ordinary spark and throttle levers. The wiring formerly gave 



Fig. 289. Drawing Showing Section through Owen Magnetic Transmission 


seven speeds forward and two reverse, but a later construction will 
probably give about twice this number. 

As is shown in Fig. 289, this consists of an electric generator, the 
field magnet of which is connected to the engine crankshaft and takes 
the place of the flywheel, the armature being connected with the 
driving shaft. This transmits the turning effort of the engine by 
means of the current established in its circuit, due to the speed 
difference of its members on what constitutes the high speed. Any 
effort exerted by the engine on one member is transmitted, prac¬ 
tically without loss, to the other member, or armature. I he clutch- 
generator member makes a very elastic clutching and transmitting 
means, but cannot transmit more than the full torque of the engine. 





































































































































































































































406 


GASOLINE AUTOMOBILES 


For higher torque, use is made of an electric motor, whose 
armature is mounted on the driving shaft and receives current from 
the first, or clutch, generator. 

In the figure, the clutch generator is shown at the left, its field 
part marked FR, the field winding F IF, and the pole pieces PP. 
This portion rotates whenever the crankshaft revolves. Within it is 
the armature A secured to the continuous shaft S, which is con¬ 
nected through the joint X with the driving shaft to the rear axle. 

The second part of the complete system is shown at the right 
and is practically a duplicate of the clutch generator. Its armature 
Ai is carried on the same shaft S as armature A. Outside this is 
the usual field part with rings FR, windings FW, pole pieces, and 
brushes B. 

Field FR can revolve without any motion of A ; in fact, it is by 
varying the relative speed of FR and A that the different speeds are 



Fig. 290. Sketch to Explain Working of Magnetic Transmission 
Courtesy of Baker-R & L Company, Cleveland, Ohio 


obtained. For instance, on direct drive the generator is short- 
circuited on itself and carries armature A with it. Then, except for 
a slippage of 4 per cent or less, between the field FR and the arma¬ 
ture A, the wheels would be driven as fast as the latter rotated. 
Lower speeds are produced by making the slippage greater. Speed 
changing, as well as starting and braking, are accomplished by means 
of the finger lever on the steering wheel. The storage battery is 
charged at a 10-ampere rate. 

Perhaps the explanation which follows will give a better idea 
to the repair man than the foregoing, which is slightly technical 
The rotating field of the generator, marked FW, is comparable to 
a horseshoe-shaped magnet B, Fig. 290, also rotated by the engine. 
The armature A at the left-hand, or engine, end of the shaft is com- 














































































































GASOLINE AUTOMOBILES 


407 


parable to the piece of steel C, which is free to rotate and which will 
do so when the field rotates and attracts it. If this were connected 
directly to the driving shaft, as Fig. 290 shows the combination 



would become a simple electromagnetic clutch and the car would have 
but one speed. On the level, one speed would be satisfactory, but 
in deep sand, on a heavy grade, or for any other severe pull, the air 
space between the rotating field and the armature would bring about 
the stalling of the engine. 

If we add a conventional 
electric motor just back of 
C, with its field fixed, or 
stationary, as at D. and its 
armature free to rotate with 
the armature shaft to which 
it is attached, about as shown 
in Fig. 291, C will not rotate 
as fast as B when meeting a 
stiff pull, although it will try 
to do so. A wire connects 
the commutator of C with 
the field coils D, and the 
electricity generated by the 
rotation of B relative to C, that is, the amount of slippage due to the 
air gap, is led through this wire to D where it acts as power, rotating 
E faster and thus acting as a booster on the propeller shaft. 



Fig. 292. Steering Wheel Quadrant of 
Owen Magnetic Car 
















































































































































REVERSE GEAR BOX FILLER 

MOTOR \ PROPELLOR SHAFT ANO JOINTS 

COLLECTOR RINGS \ \ ~ V ' ~ 

CLUTCH-GENERATOR-\ \ \ — ^ LER _ x \ PINION BEARINGS ADJUSTMENT* 


408 


GASOLINE AUTOMOBILES 



Ui UJ 
2 Q. 


Ui 

ao 

r> 

o 

a 

n. **> 
CC UJ 

O * 

u- <[ 
QC 
CO 


X 

r> 

O: 

a 

Ui 

•3C 


Fig. 293. Plan View of Complete Chassis of.Owen Magnetic Motor Car 
Courtesy of Baker-R <£■ L Company, Cleveland, Ohio 














































































GASOLINE AUTOMOBILES 


400 


By introducing variable resistance in the connecting wire, or 
rather series of wires, the speed may be varied from zero to the 
maximum, which, as it happens through this booster action, is 
considerably in excess of what it would be if the motor were driving 
directly through on high speed without any electrical or mechanical 
apparatus. The variety of speeds can be anything desired, and this 
forms the basis for naming it “The car of a thousand speeds”. As 
a matter of fact only seven speeds are provided for on the steering 
wheel, which is shown in Fig. 292, but it is perfectly feasible to 
wire up the car and arrange the quadrant to have twice this number 
or any other number, as required. On the steering post quadrant, 
the additional positions of charging, starting, and neutral are to 
be noted. The neutral position is that in which the engine is idling 
and the car standing still; or when the car is coming down a grade, 
the wheels are driving the motor which generates current in the reverse 
direction, so that the device becomes an electric brake, slowly but 
surely reducing the speed of the car. The starting position connects 
the storage battery to the generator armature in order to revolve 
the engine shaft and thus start it. The charging position can be 
used at any time to generate electricity for the storage battery. 

While this description sounds very different, the chassis is not 
unlike the average gasoline chassis with a mechanical gear shift, 
as Fig. 293, showing a view of it from above, brings out. The small 
unit just back of the motor is a mechanical reverse gear which it 
has been found advisable to use for one reason, because it gives 
all the quadrant speeds on the reverse, instead of the usual one. 
By this arrangement the car has seven fixed speeds forward and 
seven speeds reverse, together with the possible variations of both, 
which can be produced by the use of spark throttle and accelerator. 


TRANSMISSION TROUBLES AND REPAIRS 


Noise in Gear Operation. One of the most common of trans¬ 
mission troubles is a grinding noise in the operation of the gears. 
This is heard more in bevels than in spurs, but in old transmissions 
and on the lower speeds it is heard frequently. A good way to 
quiet old gears, after making sure that they are adjusted rightly 
and meshing correctly, is to use a thicker lubricant. If thick oil 
is being used, change to half-oil and half-grease or preferably all grease. 


410 


GASOLINE AUTOMOBILES 


In this respect the repair man or amateur worker may take a 
leaf out of the book of second-hand car men, who are said to “load” 
an old and very noisy transmission gear with a very thick almost 
hard grease in which is mixed some shavings, sawdust, cork, or 
similar deadening material. When this is done, a graphite grease is 
generally used, so that the shavings, cork, etc., would not show in 
case it was necessary to take off the gear-box cover. This material 
will fill up all the inequalities of the gears and shafts so that tem¬ 
porarily everything fits more tightly, and all the sounding board, 
or echo, effect is taken out of the transmission case. This sounding- 
board effect is fully as important as the grinding noise, for many 
really insignificant noises are magnified by poorly shaped gear cases 



Fig. 294. Types of Gear Pullers 


so as to appear very loud, indicating serious trouble which need 
immediate attention, when such is really not the case. 

Another source of gear-set noise is a shaft out of alignment, 
caused either by faulty setting, by worn or loose bearings, or by 
yielding or cracking of the case. If it is properly set at one end and 
is out at the other, the trouble will be more difficult to find and remedy. 

Heating. Heating is a common trouble, too, but usually this 
can be traced to lack of lubricant in an old car or to too large shafts 
or too small bearings in a new one. Sometimes the grease used will 
cause heating, particularly when long runs are made with the trans¬ 
mission working hard. This is most noticeable when the grease or 
lubricant is of such a consistency that the gears simply cut holes in 
it but do not carry any around with them or do not otherwise circu¬ 
late the lubricant. This can be remedied by making it thicker so 
the gears will cut it better, by making it thinner so they will splash 
it more, or by changing the nature of it entirely. 























GASOLINE AUTOMOBILES 


411 



Gear Pullers. One of the principal necessities for transmission 
work is a form of gear puller. These are like wheel pullers, except 
that they are smaller and more compact. In Fig. 294, a pair of 
gear pullers are shown. The one at the left is very simple, consisting 
of a heavy square bar of iron which has been bent to form a modified 
U. Then, a heavy bolt is threaded into the back of this or bottom of 
the U. This will be useful only on gears which are small enough to 
go in between the two sides of the puller, that is, between the sides 
of the U, which when in use is slipped over the gear, the screw turned 
until it touches some- 




thing solid, as the end of 
the gear shaft, and then 
the turning continued 
until the gear is 
forced off*. 

While not as simple 
as this, the form shown 
at the right has the 
advantages of handling 
much larger gears, and 
also of being adjustable. 

As the sketch shows, this 
consists of a central 
member having slotted 
ends in which a pair of 
L-shaped ends, or hooks, 
are held by a pair of 
through bolts. Then 
there is a central work¬ 
ing screw. To use, the hooks are set far enough apart to go over the 
gear, then slipped around it and hooked on the back. The central 
screw is turned up to the end of the shaft, and then the turning 
continued until the gear comes off. There are many modifications 
of these two; in fact, practically every repair shop in the land has 
its own way of making gear or wheel pullers. At any rate, every 
shop should have one. 

Pressing Gears on Shafts. The opposite of pulling off gears 
is putting them on; very often they are designed to be a press fit, 


Fig. 295. 


Method of Pressing Transmission Gear 
onto Its Shaft 








412 


GASOLINE AUTOMOBILES 


which means exerting tremendous pressure. Every repair shop 
should have some form of press for this and similar work, something 
similar to the form shown in Fig. 295. In this figure, the man is just 
beginning to apply pressure to the shaft to force it into the lower 
gear. The table must be arranged for work of this kind with a solid 
spot when the shaft does not come through, and with a hole when it 
does. The work of pressing is usually done in a few seconds, while the 
preparation, alignment, and starting of the work takes perhaps half 
an hour or more. It is work which should be done very carefully. 

One way in which arrangement can be made for pressing a 
shaft a considerable distance into a gear and, conversely, for pressing 

the shaft out of the gear is that 
shown in Fig. 296. This figure 
has the additional advantages of 
being simple, easily constructed, 
and cheap. A solid base is 
constructed with a pair of • 
hinged uprights. These can be 
dropped together with the work 
between them, forming a mod¬ 
ified triangle, the strongest 
known shape, resting upon its 
broadest side and thus having 
the greatest stability. With this 
arrangement, the press can 
used for pressing off parts. 

Diagnosis. The repair man should use a great 



Fig. 296. 


Home-Made Table for Use in Gear 
Pressing or Pulling 

Courtesy of “Motor World’’ 


readily be 

Care in 

deal of care in doping out or diagnosing the trouble in a transmission, 
for, frequently, what appears at first to be at fault turns out to be all 
right, and something else is back of the first trouble, which must be 
corrected before a remedy can be applied. Recently, a repair 
man figured that a new gear was needed to repair a transmission. 
This was received from the factory three days later, but when he 
started to put it in, he found that a bearing was defective; in fact, 
the defective bearing caused the wear in the gear. This necessitated 
a further delay of three days in order to get a new bearing. 

Poor Gear Shifting. A common transmission trouble is poor 
gear shifting. This may be due to a number of different things. 



















GASOLINE AUTOMOBILES 


413 



For one thing, the edges of the gears may be burred so that the edges 
prevent easy meshing. When this is the case, any attempt to force 
the gears into mesh only burrs up more metal and makes the situa¬ 
tion worse. Whether this is the trouble or not can be determined 
very quickly and easily by removing the transmission cover and 
feeling of the gears with the bare hand; the burred edges can readily 
be distinguished. If this is the only fault, the transmission should 
be taken down, the gears taken out and placed in a vise, and the 
burrs removed with a cold 
chisel and file. 

Poor or worn bear¬ 
ings or a bent shaft or one 

not accurately machined 
«/ 

may cause difficult shift¬ 
ing. If the bearings are 
worn, the difficulty of 
shifting will be accom¬ 
panied by much noise, 
both in shifting and after. 

The bent shaft is more 
difficult to find and equally 
difficult to fix. A new 
shaft is usually the quick¬ 
est and easiest way to 
remedv the trouble. 

Sometimes the con¬ 
trol rods or levers bind or 
stick so that the shifting 

is verv difficult. In case 
*/ 

the gears are difficult to 
“find” or will not stay in mesh, the fault may be in the shifter rod in 
the transmission case. This usually has notches to correspond to the 
various gear positions, with a steel wedge held down into these notches 
by means of a spring. The spring may have weakened, may have lost 
its temper, may have broken, or for some other reason failed to work. 
Or with the spring in good working condition, the edges of the 
grooves or notches may have worn to such an extent as to let the 
wedge slip out of, or over, them readily. 


Fig. 297. Tank and Basket for Cleaning Gears and 
Other Parts 

Courtesy of “Motor World ” 











































414 


GASOLINE AUTOMOBILES 


Cleaning Transmission Gears. When the transmission is taken 
out of the case and has to be taken apart, and particularly if it has 
not been cleaned for a long time previously, it is advisable to clean 
all the parts thoroughly before attempting to work with them. 
The best way to clean the parts is to have a special cleaning tank. 
In Fig. 297 one of these is shown, which is not unlike the baskets 
used in some hardening processes. It consists of a deep metal or 
metal-lined tank and a basket or tray, which is an easy fit in it, 
suspended from above by wire cables. The cables are brought 



together on the wall, where a ring joining the ends and a series of 
nails or hooks make it easy to hold it at any desired elevation, either 
in or out of the tank. The tank is filled preferably with kerosene. 
As soon as a part has been removed from the transmission, it is 
thrown into the basket, and when this is filled or all the parts are in 
it, it is lowered into the kerosene and allowed to stand, for a couple of 
hours if possible, but, if not, for as long as can be. When thoroughly 
soaked, the basket should be raised above the level of the liquid and 
allowed to drain thoroughly. If it can be left for an hour or so to 
































GASOLINE AUTOMOBILES 


415 


drain, all trace of kerosene will disappear, while the gears, shafts, 
and other parts will be like new. 

Lifting Out Transmissions. When the trouble has been found 
to be in the transmission case or in some part that necessitates com¬ 
plete removal, it is often a tremendous job to get the unit out. Some 
units are attached from below and are not so difficult to detach, 
lliey are lowered by means of a platform of boards set on two or 
more jacks. But when it must be removed from above and no 
overhead beam is available, the hoist shown in Fig. 298 will be found 
very handy. As will be seen from the sketch, this hoist is simply a 
triangular framework constructed from angle iron to have the 
minimum height which will allow removal of the unit. The chain 



Fig. 299. Two Forms of Useful Transmission Stands 
Courtesy of “Motor World ” 


fall is attached to a hook in the center, and the chains put around 
the case. When lifted up close into the V of the framework, the 
whole transmission can be put onto horses and moved along the 
chassis, or boards can be put under it and over the chassis frame to 
allow it to be worked there. Or, if desired, it can be lowered onto a 
creeper or other low platform with wheels and moved out of the way. 
This rigging can be used for many other similar purposes, although it 
is not suitable for the removal of an engine, radiator, or other part 
or unit which extends far above the chassis frame. 

Transmission Stands. When the transmission has been 
removed, if the work to be done upon it is all extended, a stand to 
support it is desirable; in fact, a necessity, if the work is to be done 
right. A pair of stands are shown in Fig. 299, the one at the left 
















416 


GASOLINE AUTOMOBILES 


is made from pipe fittings and angle irons in such a way that the 
width between the rails can be varied to suit the transmission or 
engine. The stand at the right is more of a specialized type. It is 
constructed for a certain transmission and has clips to support it 
in the same way that it is held in the chassis. The latter frame may be 
smaller and more compact than the former, but the wide range of 
uses to which the former can be put make it more desirable in the 
average shop. 

Working in Bearings. When a great many bearings of any 
one transmission are fitted, it is well to make a jig for working in 
the cases to an exact size for the bearings, whether these be over- 



Fig. 300. Method of Fitting Transmission Case Bearings with Dummy 

sizes or not. Such an outfit, Fig. 300, shows an aluminum trans¬ 
mission case with a pair of jigs for scraping its bearings into the case. 
These jigs are made of steel and are constructed to a very accurate 
size, the surfaces being hardened so they will show no wear. The 
jigs are painted with Prussian blue, put in place and turned, the 
markings scraped by hand, the jigs again put in place and turned, 
and this process repeated until a perfect bearing surface is obtained. 
Starting with an unknown size on the case and a known size of bearing 
which must go in it, a few of these jigs will soon save their cost in 
labor and time, by quickly producing the necessary size of case to 
take the bearings. 







GASOLINE AUTOMOBILES 


417 


Saving the Balls. If a great many ball bearings, particularly 
from transmissions, are used, and many bearings scrapped, it is 
advisable to save the balls. These balls will come in handv later for 
replacement or other uses. 

Moreover, balls are expen¬ 
sive, and good ones are hard 
to obtain. A handy way to 
take care of balls, without 
much work beyond cleaning 
thoroughly in the kerosene 
tank, is to construct a cab¬ 
inet like that seen in Fig. 301. 

There are four drawers—or 
more if desired. The bottom 
of each drawer is a steel plate 
drilled as full of holes as pos¬ 
sible of the next smaller size, 
that is, a clearance size for 
the next round figure size. 

Then the cabinet does the sorting, all balls being put into the to}) 
drawer. The next smaller size is retained in the second drawer, the 
third size in the next, and so on. When using balls out of these 
drawers, the micrometer should be used to determine their exact size. 

Handy Spring Tool. In the Ford transmission-band assembly 
there are three springs which it is difficult to assemble because of 
the trouble in holding so many things at once. To eliminate this 
trouble, the tool, shown 
in Fig. 302, made from 
flat bar stock, can be 
constructed. The han¬ 
dles, if thev could be 
called that, are pivoted 
together and carry a kind 
of flat jaw with three 

. Fig. 302. Handy Spring Tool for Ford Assembly 

notches at one end. 

When the two of these are squeezed together by means of the screw 
and handle at the other end, the flat plates will hold the three springs 
tightly enough so that all can be inserted in their proper positions 










































418 


GASOLINE AUTOMOBILES 


at once by using but one hand. Tools of this kind, which save 
a great deal of the workman’s time and thus save both time and 
money for the owner of the car, should, and in fact do, distinguish 
the well-equipped repair shop and garage from the old-fashioned 
kind which is in the business only for the money and not too par¬ 
ticular how it is gotten. 

In transmissions of the planetary type, there is little or no 
trouble except with the bands. If these are loose, the gears will 
not engage and the desired speed will not result. If they become 
soaked with grease, oil, or water, they will not work as well as if kept 
clean and, in the case of excessive grease, will slip continually. If 
the band lining becomes worn, it should be treated just as a brake 
lining is. When inspected for wear and found not badly worn but 
slippery, it may be cleaned in gasoline and then in kerosene, after 
which a saw, hacksaw, or coarse file may be used to roughen it. 
Sometimes greasy bands can be fixed temporarily—say, enough to 
get the car to a place where tools, materials, and facilities for doing 
the work are available—by sprinkling them with powdered rosin or 
fuller’s earth. The former should be used sparingly because it will 
cause the band to bite or grab hold when forcibly applied, and at times 
has been known to cut into and score a cast-iron drum. As a rule, 
planetary transmission bands should be handled in the same way as 
ordinary brake bands, as to lining and relining, roughness of surface, 
lubrication, etc. 

Possible Transmission Troubles. A combination of clutch 
and transmission in which the principal troubles incident to these 
units are indicated is presented in Fig. 303. In this type of clutch, 
the greatest possibilities of trouble lie in the burring of the discs 
or in a lack of spring adjustment. If the discs burr, the burrs can 
be filed off with a fine file, while the latter trouble is avoided by 
merely tightening the spring-adjusting bolt, trying the effect of 
this and tightening again, until the correct and satisfactory position 
is obtained. 

In transmissions, the possibilities of trouble include the following: 
burred teeth; gears worn where they slide along the shafts on keys 
or in keyways; looseness in the main bearings; and play in shifter 
rods or their locks. Where the gears clash, one against the other 
in shifting—unless the faces of each have been chamfered and rounded 



GASOLINE AUTOMOBILES 


119 


ofi nicely and are well hardened at these points—a cutting action 
which gradually wears a high burr in one or both gears is liable to 
be set up. When the two are in mesh, the burrs are on opposite 
sides and contact with the meshing gear. This contact will make 
a continuous noise. Its remedy is the removal of the gear, the 
filing off of all raised portions, the filing or grinding out of all low 
spots cut into the teeth, and subsequent hardening to make repetition 
impossible. 

If the gears have worn at the center hole where they slide on 
the shaft, either in the round hole or at the keyway, this must be 
fixed at once. In the former instance, the gear can be bushed, and 



Save, paper daskpt or mab^mcrw one 

Lx^-for wear iri shiitirg red 
Q> set screws down ^compensate for it 


Gean elites, re¬ 
adjust sprirgsfj 
file: off burrs 

besepare® 
troe. 


"Examine radial 
©- thrust bearirgs 

Lodpfor burrs or wear on gear teeth, 
or wear on shifting collars 


^lighten shifting 
forl^ fastenings 

overall 

rpys ®- Ijeyways 


close 
examination 


shaft longitud- 
if wear or shiftily) 
nas made it necessary 


Fig. 303. Transmission Troubles Illustrated 


the bushing bored out to fit the shaft, while in the latter, a slightly 
larger key may be fitted into the shaft and the keyway may he recut 
to accommodate it. Where the keys have been let into the shaft, 
they may become worn in one spot or at the ends. If the wear is all in 
the key, it can be replaced with another of the same size made slightly 
harder in the process. 

If the main bearings are of the roller type, the wear may be 
taken up by readjusting the position of the roller on the cone, but 
if they are of ball or plain bushing form, replacement is almost 
the only remedy, unless it happens that in the case of a plain bush the 
bush is split, so that something may be filed off of the two contacting 
sides, and the holes trued out to this new size. In that case, the 












420 


GASOLINE AUTOMOBILES 


advice previously given under the subject of Plain Engine Bearings 
will be applicable. 

Play in the shifting rods may be traced to one of two things: 
looseness at the connection of two rods or of a rod and a lever; or 
looseness in the bearings. The former inevitably requires a new and 
slightly larger pin driven into the place occupied by the previous 
member. Loose bushings will mean new ones if the trouble is serious, 
for this form is almost always of the solid and non-adjustable type. 
In many cases where wear occurs on a solid plain bearing used on 
the end of a plain round shaft, if peening cannot be resorted to, 
the shaft may be turned down a very little bit, say inch, the bushing 
turned out an equal amount, and a thin sleeve bushing made of this 
thickness all around and forced into the previous member. This 
saves reboring the case, which is an expensive and difficult job, 
while both the shaft and bushing jobs are simple ones. 

If a serious defect develops in the case, it may be cleaned out 
and welded. This is not a job for the amateur, but the closing of a 
simple crack, no matter how long, would be an easy proposition for 
the owner of a welding outfit; moreover, it would be a very short 
quick job. Autogenous welding should always be resorted to as soon 
as a crack or break is detected, for this may save the expense and 
delay of a whole new ca^e, the welding costing from 50 cents to $1, 
while the new case easily may amount to $50. 

SUMMARY OF TRANSMISSION TROUBLES 

Lubricating Transmission Gears. The transmission case should 
be filled with lubricant to a depth of several inches. Care should be 
exercised at frequent intervals to see that a proper amount of lubri¬ 
cant remains in the transmission case. Different makers recommend 
different kinds of lubricants for transmissions. In light cars a mixture 
often used consists of equal proportions of light grease and machine 
oil. In heavier cars a heavy graphite grease is often used. The 
proper lubricant depends upon the types of bearings used; thus for 
ball-bearing transmissions, no oil need be added. 

Change=Speed Lever Indicates Some Impediment in Transmis= 
sion. It is desirable to look for broken or mutilated gears, broken 
bearings in transmission shafts, sticking or misalignment of gear shafts 
or of their operating mechanisms. 


GASOLINE AUTOMOBILES 


421 


Adjusting Annular Bearings. Makers recommend that the 
inner race be pinched so tight that movement is impossible; the 
outer race is sometimes allowed a little freedom—.002 to .003 inch. 

GEARS 

Since the whole subject of transmission concerns itself with 
gears, it will not be out of place to discuss the gears themselves 
and describe the many different kinds in use. Speaking broadly, 
the gears used may be classified according to the position of their 
axes, relative to one another. Thus we have axes parallel and in the 
same plane; parallel but not in the same plane; at right angles and in 
the same plane; at right angles and not in the same plane; at some 
other angle than a straight or a right angle and in the same plane; 
and the same, but not in one plane. These classes give us the forms 
of gear in common use, viz, spur gears, bevel gears, helical gears, 
herringbone gears, spiral gears, and worm gears. 

TYPES OF GEAR=CUTTING MACHINES 

Before discussing these various kinds of gears, it may be wise to 
familiarize the reader with the special features of different types of 
gear-cutting machines. Formerly, the teeth were cut, one gear at 
a time, in the milling machine, this being practically a hand opera¬ 
tion, since all movements of the gear or cutter had to be made by 
hand. Later, improvements made it possible to cut more than one 
gear at a time, which resulted in lowering the cost, but did not 
eliminate the hand work. 

Step by step special machinery was developed for this work, 
until finally a perfected machine was brought out which did all the 
work. With this machine, the workman placed the cutter on 
the machine spindle, set the gear blanks into position, and started the 
machine, after which it went on automatically, cutting tooth after 
tooth to a correct shape, until the gear was finished, when it was 
again necessary for the workman to shut it off and, after taking out 
the finished gears, put in a fresh supply of gear blanks. 

Many machines have been devised and perfected in recent years 
owing to the demands of the automobile manufacturers. By having 
a battery of gear-cutting machines handled by a single man, the 
cost of gear cutting has been brought down to the absolute limit 
in addition to a.decided gain in gear accuracy. 


422 


GASOLINE AUTOMOBILES 


Whiton Gear=Cutting Machine. The Whiton automatic gear¬ 
cutting machine is shown in Fig. 304. The cutter is carried by 
the spindle A , which is journaled in a saddle B sliding upon the 
swinging carriage C, and is capable of adjustment at any angle neces¬ 
sary to cut bevel gears. The machine, as shown, is arranged for 
cutting spur gears. The cutter arbor A is driven by the pulley D at 



Fig. 304. Automatic Gear-Cutting Machine 
Courtesy of D. E. Whiton Machine Company, New London, Connecticut 

the back of the machine, acting through a system of gears not shown. 
The blank to be cut is held on an arbor fitted into the vertical spindle 
E, with its upper end supported by a center in the arm, adjustably 
clamped to the column G. The traversing screw H has a graduated 
dial. A gage provided centers the cutter, and graduated stops 
are used for setting over the cutter in bevel gear cutting and for 
setting over the blank. At J are the gears of the indexing mechanism. 






GASOLINE AUTOMOBILES 


423 

Brown and Sharpe Gear=Cutting Machine. Fig. 305 repre¬ 
sents a Brown and Sharpe gear-cutting machine. The gear blank is 
carried on an arbor fitted to the horizontal spindle A and supported 
by the outer supporting bracket B. The indexing mechanism is in 
the rear of the indexing wheel C. The cutter is carried by the cutter 
spindle D mounted in the traveling carriage E. In smaller machines 
the base upon which this carriage slides is pivoted so as to be 



Fig. 305. Number 6 Gear-Cutting Machine 
Courtesy of Brown and Sharpe Manufacturing Company, Providence, Rhode Island 


set at any required angle for cutting bevel gears. The machine is 
entirelv automatic in its action. It has an attachment for cutting 

C/ 

internal gears. 

Automatic Gear=Cutting Machine. The automatic gear-cutting 
machine built by Gould and Eberhardt is shown in Fig. 306. It is 
of the same type as that built by Brown and Sharpe and possesses 
some excellent features. The gear blank and cutter are mounted in 




424 


GASOLINE AUTOMOBILES 



a similar manner, and the adjustments are made at much the same 
points. It is furnished with attachments for hobbing worm gears 
and for cutting racks and internal gears. The one shown is not 
adapted for cutting bevel gears. 

Becker Gear=Cutting Machine. The Becker Milling Machine 
Company gear-cutting machine, Fig. 307, is of the milling-machine 
type. It was designed by Amos H. Brainard, a builder of milling 
machines. The gear blank is mounted upon an arbor fitting a taper 


Fig. 30G. “New Type” Gear-Cutting Machine Entirely Automatic for Cutting Spur Gears Only 

Courtesy of Gould and Eberhardt, Newark, New Jersey 

hole in the work spindle A or fixed upon an arbor and mounted on 
centers. The cutter is mounted upon a cutter arbor B journaled in a 
sliding saddle C whose support D is pivoted to the machine knee so as 
to be adjustable to any angle required for cutting bevel gears as well 
as spur gears. The machine is entirely automatic in its action. 

Fellows Gear Shaper. The Fellows gear shaper, shown in 
Fig. 308, is a distinct type in construction and action. The gear 
blank is mounted on the vertical work spindle A, which has on its 
lower end and within the casing B an indexing worm gear operated by 














GASOLINE AUTOMOBILES 


425 


the change gears at C. These are driven from the cone pulley D by 
means of the vertical shaft E with a very gradual but continuous 
motion as the vertically reciprocating cutter F forms the teeth on 
the blank, gradually rotating in unison with the rotation of the blank. 
The reciprocating movement of the ram carrying the cutter is pro¬ 
duced by suitable mechanism within the casing H operated by the 
shaft G. The machine is automatic in its action and cuts spur gears 



Fig. 307. Gear Cutter 

Courtesy of Becker Milling Machine Company, Hyde Park, Massachusetts 


and internal gears. A modified form of machine is adapted to cutting 
the teeth of racks. The cutting action is that of planing. 

Gleason Gear Planer. The Gleason gear planer is shown in 
Fig. 309. It is an excellently designed machine with a single tool 
having a narrow rounded cutting point for planing gear teeth. The 
gear blank A is mounted on a horizontal spindle having at its rear 
end a suitable automatic indexing mechanism B. The tool C is 
carried in a reciprocating tool block D which travels upon a swing- 





42G 


GASOLINE AUTOMOBILES 


ing carriage pivoted at E directly under the apex of the base cone of 
the gear blank. The exact curve and direction of its feed are con¬ 
trolled by one of the formers, mounted upon the triangular former 
carrier, which may be rotated so as to bring either former up to its 
operative position, making a rest and guide on the outer end of the 
swinging carriage for the friction roller K. Of the three formers, one 



Fig. 308. Gear Shaper 

Courtesy of Fellows Gear Shaper Company, Springfield, Vermont 


is used for a roughing cut, and the other two for the upper and under 
sides of the tooth. Being placed at a considerable distance from the 
pivot upon which the carriage swings, they are made many times 
larger than the tooth, and great accuracy of form is thereby secured. 
The roughing cut is frequently made with a rotating cutter on an 
ordinary gear-cutting machine. Modifications of this machine are 
built upon the same principle specially for cutting spur gears. 





















GASOLINE AUTOMOBILES 


427 


bilgram Gear-Planing Machine. The Bilgram gear-planing 
machine, shown in Fig. 310, operates upon a principle similar to that 



Fig. 309. Gear Planer 

Courtesy of Gleason Tool Company, Rochester, New York 





Fig. 310. Gear-Planing Machine 


of the machine just described, but with this important difference. 
In the Gleason machine, the tool moves so as to trace the exact 
contour of the side of the gear tooth, in addition to its reciprocating 














































































428 


GASOLINE AUTOMOBILES 


movement for cutting. In the Bilgram machine, on the other hand, 
the tool has only a reciprocating motion, while the gear blank and 
its supporting mechanism are given the rolling motion similar to that 
imparted by one rotating gear to another, which is that of a rolling 
cone. To accomplish this motion, the axis must, in the first place, be 
moved in the manner of a conical pendulum; therefore, the bearing 
of the arbor which carries the blank is secured in an inclined position 
between two uprights to a semicircular horizontal plate, which can be 
oscillated on a vertical axis passing through the apex of the base cone 
of the blank. To complete the rolling action, the arbor must, in the 
second place, receive simultaneously the proper rotation; this effect 
is produced in the machine by having a portion of a cone (correspond¬ 
ing with the pitch cone of the blank), attached to the arbor and held 
by two flexible steel bands stretched in opposite directions, one end 
being attached to the cone and the other to a fixed part of the mech¬ 
anism, thus preventing this cone from making any but a rolling motion 
when the arbor receives the conical swinging motion. In the engrav¬ 
ing, A is the blank to be cut, B the ram carrying the cutting tool, and 
C the indexing and rolling mechanism. 

TYPES OF GEARS IN AUTOMOBILES 

Spur Gears. A spur gear is not only by far the most common 
kind of gear, but is also the easiest to describe, consisting, as it does, 
of a round flat disc with teeth cut in its circumference, i.e., around 
the periphery of the disc, as shown in Fig. 311. 

Bevel Gears. Bevel gears, in which the shafts are at right 
angles and in the same plane or in the same plane but not at 
right angles, are more difficult to cut and are.therefore less used. 
They are now cut, like the spurs, in an automatic or nearly automatic 
machine, which requires little attention, but which does require 
more care than the spur-gear machine. Both spurs and bevels 
sometimes require a chamfered tooth edge; spur gears as used in the 
Panhard, or clash-gear, transmission are always in need of it. This 
work was formerly done by hand, but now a special machine has been 
manufactured for this purpose. 

There are no real restrictions against the use of the spur and 
bevel, either or both being used interchangeably. Very often they 
are used in combinations which appear peculiar, as the one sliov :i 


GASOLINE AUTOMOBILES 


429 


in h ig. 311. 1 his is the final drive and reduction gear of the Autocar 

commercial cars, made by the Autocar Company, Ardmore, Penn¬ 
sylvania. In this gear, it will be noticed that the drive from the engine 
is through bevels to an intermediate shaft and that the final drive 
is by spur gears. 

Helical and Herringbone Gears. In situations where quiet 
. running is deemed necessary, the use of a helical gear frequently finds 
favor, since it accomplishes the desired result, although the cost of 



Fig. 311. Combination of Gears in the Autocar Final Drive 


cutting is high. Of late, these gears have come into general use for 
camshaft drives and similar places. A pair of helical gears set so that 
the helices run in opposite directions forms a herringbone gear. 
This is even more quiet in its action than the single helix and pos¬ 
sesses other virtues as well. One well-known firm has adopted it for 
camshaft driving gears and makes it as described to save cutting- 
cost, as the cost of cutting a true herringbone would be prohibitive. 
So a pair of helical gears of opposite direction are set back to back and 
riveted or otherwise fastened together, forming a herringbone gear at 
a low cost. Both of these may be used when the two shafts are par- 






430 


GASOLINE AUTOMOBILES 


allel and in the same plane, but for all cases where the shafts are 
neither in the same plane nor parallel, some form of spiral gear must 
be made use of. 

Spiral Gears. Spiral gears, as such, are not generally under¬ 
stood, but that variety of the spiral known as the worm gear is 
very simple and easily understood and it has attained much popu¬ 
larity within the past few years. This popularity has been due, in 
part, to superior facilities for cutting correct worms and gears, but, in 
the main, to a superior knowledge of the principles upon which the 
worm works and of the things which spelled failure or success. Thus, 
one of the earliest experimenters in this line laid down the law that the 
rubbing velocity should not exceed 300 feet per minute if success was 
desired or in rotary speed about 80 to 100 revolutions. For auto¬ 
mobile use, this was out of the question; but later experimenters 
found that these results only attached to the forms of gear used by 
the early workers and did not apply to a strictly modern gear laid 
down on scientific principles. 

The mistake made was in the pitch angle of the worm, which 
was formerly made small, nothing over 15 degrees being attempted. 
This was the item that was at fault and that caused this very useful 
and efficient mode of driving to fall into disuse. As soon as this 
fact was ascertained and larger pitch angles utilized, better results 
were obtained, until, with 20-degree angles, 700 feet per minute pitch¬ 
line velocity was attained, followed shortly by the use of even higher 
angles, resulting even more successfully. As the efficiency depends 
directly upon the pitch angle, these changes brought the efficiency 
of this form of gearing from the former despised 30, 40, and some¬ 
times 50 per cent up to 87, 88, and even 90 per cent, thus putting it 
on a par with all but the very best of spur gears and above bevel 
gearing. In fact, in the light of modern knowledge of worm gears, 
it could easily be said, without departing from the truth, that it 
is possible to obtain from this form an efficiency of 93 per cent. In 
automobile work, the worm gear has been used mostly for steering 
gears and final drives. In the former, its irreversible quality is 
brought out, while in the latter, this quality must be made subordi¬ 
nate to a great reduction, which may be attained in a very small 
compact space. Many modern machines make use of worm gears. 
Some of the users are: the Jeffery, Baker, Detroit, Hupp-Yeats, and 


GASOLINE AUTOMOBILES 


431 





Woods electrics; Pierce, Packard, Riker, Mack, Atterbury, Blair, 
Chase, Gramm, G.M.C., Hulburt, Moreland, Standard, Sterling, and 
other trucks; Dennis (English) busses and trucks and Greenwood and 
Batley (English) trucks. 


Fig. 312. Rear View of Timken Worm-Driven Rear Axle 
Courtesy of Timken-Detroit Axle Company, Detroit, Michigan 

Spiral Bevels. The spiral bevel is a new development, having 
been brought out in 1914 as a compromise between the worm and the 


Fig. 313. Worm Gear Applied to Rear Axle Drive of Touring Car 


Fig. 314. Worm Used on Locomobile Trucks 
Courtesy of Locomobile Company of America, Bridgeport, Connecticut 

straight bevel. As such, it is supposed to have practically all the 
advantages of both, except that it does not afford the great speed 

















432 


GASOLINE AUTOMOBILES 



reduction that can be accomplished with a worm in the same space, 
being more like the bevel in this respect. 

Among those using the spiral bevel are the Packard, Cadillac, 
Reo, Stearns-Knight, Velie, Kline, Apperson, Buick, Chalmers, 
Chandler, Cole, Haynes, Hupmobile, Jackson, King, Locomobile, and 
many others. Figs. 312 and 313 show applications of the worm; 

Fig. 314, a detail of the 
worm as used on a prom¬ 
inent truck; and Fig. 315, 
a detail of the spiral bevel 
as used on a prominent 
car. 

Worm Gears. Prog¬ 
ress in the application 
of worm gears for rear- 
axle use has been con¬ 
siderable in the last few 
years. In one respect, 
at least, designers have 
found it an advan¬ 
tage. The top position 
for the worm was not 
much used at first, as it 
was thought impossible 
for it to receive sufficient 
lubricant there. Conse¬ 
quently, it was always 
placed in the bottom posi¬ 
tion, which cut down the 
clearance considerably; in 
this position the clearance 
was less than with the 
ordinary bevel. With the 
could be lubricated in a satisfactory 


Fig. 315. 


Cadillac Helical-Bevel Driving Gear 
and Pinion 


proof that the worm 


manner in the top position, the majority of gears are so placed, 


thus converting what was formerly a disadvantage into an 
advantage, for in the upper position the clearance is greater 
than with bevel gears. This is shown quite clearly in Fig. 312, 








GASOLINE AUTOMOBILES 


433 


where it will be noted that the worm-gear housing in the center 
is actually higher than are the brake drums at either end of the axle. 
This, too, despite the fact that a truss rod passes beneath the 
center of the axle. For heavy trucks, especially, and for electric pleas¬ 
ure cars, the worm has proved an ideal drive. In these situations, 
there is the condition of high-engine or electric-motor speed, coupled 
with low-vehicle speed requirements, which necessitate a considerable 
reduction. As pointed out, the worm gives this in a small space. 

For 1916, the very apparent tendency in final drives is toward 
spiral bevels for pleasure cars and worms for electrics and trucks. 
The tendency toward spirals is very great, amounting practically 
to a landslide, 57 per cent using it against 10 for 1915. The devel¬ 
opment of special machinery for cutting these gears and the under¬ 
standing of their use has brought this about. In the truck field 
there has been a similar movement toward the worm, due to similar 
causes. 

Gear Pitch and Faces. The manufacturers of transmissions and 
of gears for them do not agree as to the best gears. Neither do they 
agree as to which gears are most quiet or most efficient. In general, 
coarse-pitch stub-tooth gears are gaining faster than any other form. 
The 6-8 pitch is fairly general for gears of f-inch and f-inch face, 
and 4-5 pitch for wider gears. One manufacturer, Warner, con¬ 
siders the finer pitch gears and narrower faces as less likely to make 
noise, since they will not distort as much in hardening as wider gears. 
In this, other manufacturers agree, but there are some who claim to 
have had both quiet and noisy operation with both fine and coarse 
pitch. The tendency toward compactness has not increased 
transmission-gear faces any appreciable amount, nor has the 
increased use of better steels and better hardening processes lessened 
the size of the four noticeably. 

Gear Troubles. Most of the common gear troubles have been 
previously covered at the end of transmissions. There is not as 
much trouble with gears today as there was several years ago. This 
is due to better design, better materials, better processes, and better 
assembling on the part of manufacturers and to more skill in handling, 
caring for, and adjusting on the part of owners. Of course, the 
repair man still finds plenty to do, but the percentage of gear repairs 
is relatively less than ever before. 


434 


GASOLINE AUTOMOBILES 


SUMMARY OF INSTRUCTIONS 
CLUTCHES 

Q. Why is a clutch needed? 

A. The clutch is needed to disconnect the rest of the drive 
from the engine. The gasoline engine cannot start under a load but 
must first get up speed. By means of the clutch, which can be 
thrown out, the engine is allowed to run alone and get up the neces¬ 
sary speed, then the load or drive can be thrown on. This is just as 
true of the stationary gas engine as of the automobile, motor boat, 
or aeroplane power plant. 

Q. How does the clutch act? 

A. It is designed and constructed so that the amount of friction 
surface, with the spring pressure provided, is sufficient to transmit 
the whole power of the engine (and slightly more as a factor of 
safety) when the clutch is in. In addition, it is so designed and con¬ 
structed that when the clutch is out the spring pressure is taken up 
in such a way as to be self-contained, that is, its thrust is carried to 
a member outside of the clutch itself which is able to withstand this 
thrust. In this way, when the clutch is out, the engine is entirely 
free, and when the clutch is in, the connection is such that it will 
carry more than the maximum power of the engine. 

Q. To what type of clutch does this apply? 

A. This applies to all clutches, regardless of type or design, 
with the single exception of clutches on traction engines or on agri¬ 
cultural tractors. These are designed in the same way but work just 
the opposite, being engaged only when the clutch pedal is pressed and 
disengaged when it is released. On this account, the clutch is 
arranged so that it can be set to be in all the time or out all the time. 
With this exception, the arrangement described applies to all internal- 
combustion engines, although clutches vary widely in type, size 
and arrangement. 

Q. What are some of the most popular forms of automobile 
clutches? 

A. The multiple-disc and the cone divide honors; and there are 
a few expanding- and contracting-band forms and some miscellaneous 
types. The first two included almost 94 per cent of the total in 1914, 
over 95 in 1915, and almost 97 in 1916. 


GASOLINE AUTOMOBILES 


435 


Q. What are the two divisions of the cone form? 

A. The cone form is made in two ways, the direct form and 
the indirect form. The direct form lias the cone introduced directly 
into the flywheel, which is tapered inwards for this purpose. This 
makes it a very simple device to construct, the machining of the fly¬ 
wheel forming the female portion of the clutching surface. The indi¬ 
rect form, or inverted cone, differs in that the female portion is made 
as a separate flange bolted to the flywheel and tapering outward. 
The cone is placed inside of this, so that it works out against the 
clutching surface instead of in against this surface, as in the direct type. 

Q. What are the relative advantages of the two forms? 

A. The indirect is little used now, although it was popular years 
ago. The extra bolted-on inverted cone adds to the flywheel weight, 
for it is large and heavy and gives considerable flywheel effect. How¬ 
ever, the flywheel is simplified. The spring is enclosed between the 
flywheel and the cone, this being considered an advantage in the early 
days but now considered a disadvantage because it is inaccessible for 
inspection or adjustment. The cone is pushed in—away from the 
clutching surface—to disconnect it, while on the more simple direct 
type, the cone is pushed out—away from the clutching surface—to 
disconnect. 

Q. What are the divisions of the disc clutch? 

A. Disc clutches are generally grouped according to lubrication, 
those which run in oil being called wet, and those which run without 
lubricant of any kind being called dry. In addition, a distinction is 
generally made between the disc clutch with a very few plates (one, 
two, or three), usually called a plate clutch, and the form with many 
plates (10 or more) which is called a multiple-disc clutch. Either 
plate or multiple form may run wet or dry. 

Q. Explain the difference between the wet and dry multiple 


forms. 

A. In the wet form, the plates, or discs, are plain steel and are 
submerged in oil, the entire clutch housing being filled with oil. The 
clutch discs work steel face against steel face, the action of the spring 
when the clutch is let in gradually squeezing out the oil from between 
the faces. This gradual squeezing out of the oil gives this form its 
gradual-application quality, for with six or seven pairs of discs the 
squeezing-out process takes an appreciable length of time. In the 


43G 


GASOLINE AUTOMOBILES 


dry form, the plates are ordinarily faced with a special clutching 
surface of woven asbestos fabric similar to brake lining, this being 
placed upon every alternate disc, that is, the actual clutching surfaces 
consist of steel and fabric alternating. The general method of con¬ 
struction is to take one set, say the inner discs, and face both sides of 
each one. Then none of the outer discs are faced, so that when the 
clutch is assembled there is a steel face against each fabric face. This 
form is run absolutely dry; in fact, considerable pains is taken in 
design and assembly to keep out any form of lubricant. 

Q. Explain the difference between the plate and the multiple- 
disc forms. 

A. In the multiple-disc form, a considerable number, say 11, 13, 
15, or some such number of discs, is used; the smaller number, as 5, 
G, 7, etc., being the driving, and the larger half, as 8, 9, 10, etc., being 
the driven. In the plate form, a very small number of plates of the 
largest size which the flywheel will allow is used. As a rule, the fly¬ 
wheel inner surface is machined out to form one of the surfaces, the 
engaging or disengaging member another, and a single disc between; 
or, perhaps, another large disc is fixed to the flywheel and two discs 
used between this and the other two surfaces. The plate form has the 
advantages of a small number of parts and of compactness; but, on 
the other hand, the discs are so large and heavy that assembling is 
not so easy and a considerable flywheel effect is produced. More¬ 
over, it is not so easy to produce an absolutely flat surface in the 
larger sizes, for which reason the clutching is not so even and smooth. 
In the smaller sizes, no attempt is made at perfectly flat surfaces, as 
the inequalities balance one another. 

Q. What is the general tendency in cone=clutch surfaces? 

A. As to size, the tendency is toward larger diameters and 
smaller or narrowed clutch faces. As to materials, asbestos woven 
fabric is gradually replacing leather. Light springs under the fabric 
form the means of gradual engagement, corks going out with the 
leather with which they were used. 

Q. What is the general form of the clutch spring? 

A. Formerly, all clutch springs were of spring wire of the maxi¬ 
mum possible diameter and, therefore, very stiff. The modern 
tendency is toward a distribution of spring pressure by means of a 
number of smaller weaker springs. The former method almost invari- 


GASOLINE AUTOMOBILES 


437 


ably called for complete enclosure, making adjustments and replace¬ 
ments difficult. The smaller springs are usually placed outside, 
so that they can be adjusted or replaced easily and quickly. It has 
been found, too, that by using a large number, say 6, 7, or more, 
distributed around the clutching surface, a much lighter spring pres¬ 
sure can be used with equally good effect. In fact, many modern cars 
have so light a clutch spring that it can be disengaged with one finger. 

Q. How does the contracting=band clutch work? 

A. It has two half-bands which the clutching mechanism draws 
tight against a drum. In effect, a contracting-band clutch is like a 
band brake, except that the braking band is in two halves and operates 
from the center instead of from the exterior surface. 

Q. Is this a popular form? 

A. No. It is rapidly going out of use; only one or two American 
cars, with perhaps the same number in Europe, are now using it. 

Q. How does the expanding=band clutch work? 

A. In a somewhat similar manner to the expanding, or internal, 
brake; that is, it has two segments of fairly stiff metal section, which 
the movement of a cam, or expander, presses outward against the 
inside of the clutch drum (or inside face of the flywheel). This cam, 
or expander, is worked by the movement of the clutch pedal, or spring 
—outward so as to expand the band and take hold of the drum for 
engagement; inward so as to allow the band to contract. 

Q. Is this type gaining in popularity? 

A. No. On the contrary, it is losing so rapidly that there are 
practically no cars built in this country with it, although a number 
of old cars with this form are still running. 

Q. What is the usual position of the clutch? 

A. Within the flywheel. This saves a great deal of space, a 
number of parts, and considerable weight. 

Q. Why is this position used so freely? 

A. Partly because of the savings just mentioned, and partly 
because of the rapidly growing use of unit-power plants which forces 
this location. With the engine and transmission as a unit and the 
necessity for the clutch being between them, the flywheel interior is 
about the only place for the clutch. 

Q. How can the surface, and thus the transmitting power, of 

clutch discs be increased? 


438 


GASOLINE AUTOMOBILES 


A. By the use of other than plane surfaces. Thus, in the Ilele- 
Shaw form each disc is made with a small cone projecting from it. 
The outside of this engages with the interior of the cone on the next. 
Other forms have half-cone or other inclined surfaces and half-plane 
surfaces. As a straight line is the shortest distance between two 
points, so a plane flat surface gives the smallest area between any two 
points in parallel surfaces. From this it is apparent that any surface 
not plane offers a greater area than does the plane one. However, 
the plane surface is so much easier and cheaper to make, use, replace, 
etc., that it has gradually driven out all these forms with greater sur¬ 
face despite their advantages in the way of transmitting power. 

Q. What causes a slipping cone clutch? 

A. A slipping cone clutch is generally caused by oil, grease, or 
other lubricant on the clutching surface or by a weak spring. 

Q. How can this be remedied? 

A. The surface can be cleaned with kerosene, then with gaso¬ 
line, and dried. Or, if the surface is glazed, it can be roughened by 
using a file. Or, if the slipping occurs out on the road and no tools 
are available, any powder or fine material which will give roughness 
can be used. It is possible to get home with a slipping cone clutch 
by de-clutching and forcing in some sand. Of course, this is not 
advisable, but it works in an emergency. 

Q. What causes a disc clutch to slip? 

A. In a metal-to-metal type, a burred plate or a weak spring 
or a very thin oil which can not all be squeezed out will prevent 
engagement. The two latter causes are easily remedied; the former 
means removing the clutch and taking it apart to find the plate which 
is burred or roughened. In a faced, or dry disc, clutch slipping may 
be caused by oil, grease, or other lubricant getting in on the surfaces 
or by a weak spring. 

Q. What other things may cause a clutch to slip? 

A. The pedal may be held out, when it appears to be in, by the 
emergency brake interlock, by a bent or twisted rod, by a rod which 
presses against something, by a tight-fitting pin in one of the con¬ 
nections, by a worn pin, or by a bent-clutch spider which cannot 
contact all over because of this bend. 

Questions for Home Study 

1. Describe in detail the construction of the Studebaker clutch. 


GASOLINE AUTOMOBILES 


439 


2. Tell how you would adjust the Stearns-Knight clutch springs. 

3. Give the method of removing and replacing a clutch spring 
in the Warner clutch. 

4. If springs under the clutch facing of a cone clutch do not 
produce gradual engagement, what is the matter, and how would you 
remedy it? 

5. How does the Cadillac clutch work? 

6. How does it differ from other clutches of the same type? 

7. How would you lubricate a clutch bearing, with what, and 
how often? 

8. Describe a quick, easy method of replacing corks in a clutch. 

9. How would you construct a device to hold clutch springs 
while replacing them? 


TRANSMISSIONS 

Q. What is the purpose of the transmission in a motor car? 

A. To allow variations in the speed of the car forward from the 
lowest to the highest, and for reverse, without varying the motor 
speed greatly. 

Q. Why cannot the engine speed be varied directly, doing 
away with the transmission? 

A. The lowest speed used in cars ordinarily would not be pos¬ 
sible with the present engine, since it could not be throttled down 
slow enough. Again, if the gearing were such as to give the present 
lowest car speeds with the engine low speed, then for maximum engine 
speeds the highest possible car speed would be very low. In short, 
gearing is necessary to give a greater variation than is possible with 
the engine alone. Further, reverse could not be obtained without 
additional gears and this would necessitate also a method of shifting 
the reverse gear into, and out of, mesh. Thus, all the requirements of 
the modern gear transmission would be necessary for reverse alone. 

Q. Show by the use of figures the impossibility of doing with= 
out the transmission. 

A. The circumference of 34-inch wheels is 136.8 inches, or 11.4 
feet. With the engine geared direct to the wheels, the speed of the 
latter would be directly proportional to the former, considering the 
gear reduction. If an average present-day gear reduction of 3.8 to 1 
be considered at 240 r.p.m., which is very low, the car would make 


440 


GASOLINE AUTOMOBILES 


10.3 m.p.h. as its lowest possible speed. And at 2400 r.p.m.—a high 
maximum for an engine with as low a speed as 240—the highest car 
speed would be 103 m.p.h. As the average roads would not allow this 
high a speed, and as the average car has a low speed approximating 
3 m.p.h., it is apparent that the gear ratio is too high. By lowering 
this to 12 to 1 at a low speed of 264 r.p.m. of the engine, a low car 
speed of 2.85 m.p.h. would be obtained. And with 2640 r.p.m. as the 
highest engine speed, the highest car speed would be only 28.5 m.p.h. 
From these two extremes, it is apparent that direct gearing without 
a transmission is not feasible. 

Q. What are the general classes of transmission now in use? 

A. There are five general classes: sliding gear, individual clutch, 
planetary, friction, and miscellaneous types. The first named is most 
popular and constitutes perhaps 90 or more per cent of all the cars 
now built. The individual clutch is really a modification of the slid¬ 
ing gear, but is not widely used—not to exceed 3 or 4 per cent. The 
planetary is the most simple form to operate but, unlike the others, 
is limited as to the number of possible speeds. Practically the only 
American maker using this today is Ford. The friction form was 
intended to give a maximum number of speeds with maximum sim¬ 
plicity. It does this, but other faults offset these advantages. Metz 
is about the only American car-maker using it regularly. The mis¬ 
cellaneous transmissions include what might be called the unproved 
inventions—forms which have not been tried out sufficiently to be 
proved successes. Consequently, this class is small. It includes 
hydraulic, electric, magnetic, and various other forms of transmissions. 

Q. What is the average number of speeds? 

A. Three is the most popular number, four is found on a number 
of high-class cars, the planetary can give but two, the friction form 
may give five or more, the only magnetic form on the market gives 
seven. In general, three is considered sufficient; even the highest- 
priced makers are gradually giving up the use of four-speed gear 
boxes, and the number of these is less each year. 

Q. What are the three methods of gear shifting now in use? 

A. The selective accounts for about 94 per cent, the progressive 
form is not used by more than 2 or 3, and electric shifting is used by 
but two makers. 

Q. How does the selective form work? 





GASOLINE AUTOMOBILES 


441 


A. The operator is at liberty to select any gear he desires and 
to go directly to that speed from the speed which he is using. This 
means with common sense reservations; for instance, it would be 
foolish to go from high to reverse, although this is possible in this 
form. 

Q. How is this accomplished? 

A. Within the gear box, the gears are shifted by forms, and the 
quadrant arrangement is such that the driver can shift his lever so as 
to pick up the fork which will give the desired speed. Usually there 
are but two shifting members (in the three-speed form), one giving 
low speed and reverse, the other intermediate and high. Having 
picked up the low and reverse fork, he can shift his lever forward for 
low and backward for reverse; similarly, with the other fork for 
second and third speeds. 

Q. How does the progressive form work? 

A. In this type of gear box, the speeds must be used in succes¬ 
sion—first the low, then second, then high, and when slowing down 
from high, to second, then low, then reverse. For instance, if driving 
in high and a turn is passed in a narrow road, it would be necessary 
to shift down to second, then to low, then to reverse. The driver 
could now back his car past the street into a position which would 
enable him to make the turn. Then he could speed up the car again 
by using first low speed, then second, and finally high. This maneu¬ 
ver could not be accomplished in any other way. In the same cir¬ 
cumstances with a selective gear, the car could be brought to a dead 
stop with the brakes, an immediate shift to reverse effected, the car 
backed up, and the gears shifted to low and then high speed forward, 
thus doing the same thing as before with half as many changes. 

Q. How is the high speed generally effected? 

A. High speed in all modern transmissions is a direct drive so 
that none of the various gear reductions are in use. This method 
reduces the amount of noise by eliminating at once the meshing of 
two sets of gears, the average high-speed direct drive being effected 
by clutching one gear up to another. 

Q. Is this arrangement always used? 

A. No. In some four-speed gears the highest speed is a geared- 
up form, and the direct drive is used on third speed. This is done with 
the idea of securing the silence of the direct drive for all average 


442 


GASOLINE AUTOMOBILES 


rapid driving, while the geared-up form gives an extraordinary speed 
for emergencies where noise is immaterial. 

Q. In the electric gear shifter, how is the movement of gears 
effected? 

A. The shifter is made with a series of electromagnets, or sole¬ 
noids, one for each speed and one for reverse. Current flows to these 
when the proper button is pressed. It is well known that when an 
electric current is passed through an electromagnet of the solenoid 
type, the rod, or bar, inside of it is drawn forward. This arrangement 
produces the speed corresponding to the button pressed. In actual 
practice, the current does not flow until the clutch pedal is depressed 
after the button has been pressed. 

Q. Where is the transmission located? 

A. Excluding freak forms, there are four general positions: in 
unit with the motor; amidships in unit with the clutch; amidships 
but separated from the clutch and in unit with the forward end of the 
driving shaft; and in unit with the rear axle. 

Q. Are these same locations used on motor trucks? 

A. Yes. Except that the third class is sometimes modified with 
chain drive, so that the transmission is amidships but in unit with 
the jackshaft. 

Q. Which of these is most popular? 

A. The form in which the transmission is grouped with the 
motor and clutch, that is, the unit power plant, is now the most 
popular, and the tendency among the makers is to make it more so. 
It is gaining at the expense of all other locations. 

Q. What difference is noted in gasoline railway=car trans= 
missions? 

A. As all speeds must be used in the reverse direction, the design 
is so modified as to allow the driver first to choose the direction and 
then to utilize all his transmission speeds in that direction. 

Q. What is the difference between individual clutch and other 
transmissions, particularly the sliding=gear type? 

A. In the individual-clutch type, no one of the gears is fixed to 
its shaft, but an individual clutch is provided for each. The purpose 
of this is to clutch the gear to its shaft so that it can drive or be 
driven. When shifting gears, the driver moves the usual lever in the 
usual way, but within the transmission this lever, instead of moving 



GASOLINE AUTOMOBILES 


443 


a gear on a shaft to which it is keyed, moves a clutch which keys the 
desired gear to the shaft. 

Q. What is the advantage of this over sliding gears? 

A. In the sliding gear, the moving members must take the drive 
and transmit the power in addition to withstanding the shocks and 
destructive action of shifting or meshing. In the individual clutch 
form, the gears have only to transmit the power, while the individual 
clutches have only the shocks and destructive action of shifting. 

Q. How are gears pressed onto their shafts? 

A. Usually by means of a hydraulic or a power press—one 
capable of exerting a pressure of many tons. Generally, it is easier 
to lay the gear out on the press table and press the shaft down into 
it, than the reverse. 

Q. How are pressed=on gears removed? 

A. The process of pressing on is reversed, and the gear is sup¬ 
ported in such a way that the shaft can be pressed, or forced, out of it. 

Q. How is the transmission removed from the chassis? 

A. The usual method in well-equipped shops is to put a rope 
or chain sling or special cradle around the transmission, then to lift 
it vertically upwards by means of a block and tackle, electric or pneu¬ 
matic overhead hoist, chain block attached to overhead tracks, or 
portable crane. 

Q. How are bearings worked in? 

A. After slow careful fitting by hand for both diameter and 
length, using a dummy shaft with dummy bearings, the real bearings 
should be put in place and run-in for several hours, using power from 
a line shaft. Transmission bearings should be run-in the same as 
engine bearings, set up somewhat tight and with an excess of oil. 
Questions for Home Study 

1. Describe the construction of the Cadillac and Winton trans¬ 
missions, a railway transmission, the Mack truck, the Ford planetary, 
a friction form, and a magnetic type. 

2. How would you adjust the shafts longitudinally in the 
Stearns transmission? 

3. Tell how to construct a stand for gear pressing. 

4. Gi ve a thorough method of cleaning a transmission. 

5. What are the usual gear pitches? 

6. What is meant by the pitch of a gear? 



SECTION OF NASH CAR, SHOWING ENGINE AND TRANSMISSION DETAILS AND REAR SPRING SUSPENSION 

Courtesy of The Nash Motors Company, Kenosha, Wisconsin 
















GASOLINE AUTOMOBILES 

PART V 


STEERING GROUP 

The mechanisms by which steering is effected are among the 
most important features of a car, if not actually the most important. 
The truth of this statement will be realized when attention is called 
to the fact that safe steering is the final requisite that has made the 
modern high speeds possible, for without safe and dependable steering 
gears, no racing driver would dare to run a machine at a high rate of 
speed, knowing that at any minute the unsafe steering apparatus 
might shift the control, thus allowing the front wheels to waver and 
the car to run into some obstruction by the roadside. 

The same argument applies in an even greater degree to the 
case of the non-professional driver, who wants to be on the safe side 
even more, perhaps, than do the dare-devils who drive racing cars. 
Nearly all of our roads are curved and, to make all of these turns 
with safety, the steering gear must be reliable. Again, in mountain¬ 
ous country where there may be a sheer drop at the roadside of 
hundreds of feet, it becomes necessary that the steering mechanism 
be very accurate and that it obey, at once, the slightest move 
on the driver’s part. To secure this accuracy, there must be no lost 
motion or wear of the interrelated parts. 

These things mean that the whole steering mechanism must be 
safe and reliable; strong and accurate; well made and carefully fitted; 
well cared for; and finally, the design and construction must be 
based on a theoretically correct principle, for otherwise the mechanical 
refinements will have been wasted. Perhaps it will be more logical 
to treat the mechanical requirements first by showing how the 
present type has been evolved from the failures of earlier forms. 

STEERING GEARS 

General Requirements. In turning a corner a car follows a 
curve, the outer wheels obviously following curves of longer radius 
than do the inner wheels and, therefore, traveling farther. In 



440 


GASOLINE AUTOMOBILES 


straight-ahead running, the wheels run parallel at all times and 
travel the same distance. These two facts are the basic ones which 
make the steering action so complicated: First, that on straight¬ 
ahead running the wheels must travel the same distance; and second, 
that on turning curves the outer wheels, whichever they may be, 
must travel a greater distance. 

This double requirement leads to the usual form of steering 
arrangement, called after its inventor, the “Ackerman”. It was 
Ackerman who brought out the first vehicle in which the front 
wheels were mounted upon pivoted-axle ends, these ends being pivoted 
on the extremities of the central part of a fixed axle, while the pivoted 
ends carried one lever each. These levers were connected together 
by means of a cross-rod, while at one end another rod was attached, 
which was used to move the wheels. By moving this latter rod, 
both wheels were compelled to turn about their pivot points, since 
the cross-rod joined them together, and if one moved the other had 
to move also. This was Ackerman’s substitute for the fifth wheel 
which had been used up to that time and is even today on all horse- 
drawn vehicles. 

Inclining Axle Pivots. The situation is further complicated 
by the fact that the ideal arrangement, that is, the fixing of the steer¬ 
ing pivot at the center of the turning wheel in order to allow the maxi¬ 
mum turning movement for the minimum motion of the hand, is not 
suitable for general use. In practice, however, it is placed as close 
to the ideal position as possible, which, in the ordinary case, is within 
three to six inches. 

This approximation to the ideal has been made by inclining the 
stud-axle pivot inward, so that its center line prolonged would strike 
the ground at a point coincident with the center line of the tire. This 
same result is also brought about by inclining the stud axle itself 
downward. The construction gives added safety, in that the force 
of head-on collisions is supposed to be delivered at or near the line 
of incidence. 

The axle-spindle center may be brought close to the wheel hub 
by means of a double yoke, but this was tried and abandoned as 
too cumbersome for the results effected. A method of placing the 
steering pivot in the center of the wheel was also developed. In this 
case the pivot was enclosed in a hollow hub; but as this made the 


GASOLINE AUTOMOBILES 


447 


pivot, which is liable to wear, inaccessible, it also was abandoned. 
However, later tendencies point toward a revival of this construction. 

The result is that today we are using a form which, though far 
from being ideal, fulfills every practical requirement. This form is 
usually constructed as in Fig. 316, which shows a skeleton plan view 
of an automobile. In this, the line AB represents in length, posi¬ 
tion, and direction, the front axle of a car, while ML represents 
in a similar manner the rear axle. A and B also are the pivot points 
for the axle-stud ends or, as they are more commonly called, the 




Fig. 316. 



Diagram of Steering Connections 


steering knuckles or steering pivots, which are represented by the 
lines AD and BC. 

The rear (or front, as the case may be) ends of the steering 
knuckles are joined by the connecting rod DC. The Ackerman con¬ 
struction is such that the center lines of the steering arms, or levers, 
AD and BC, prolonged, must pass through the center point of the 
rear axle at K; the reason for this is that the front wheels are sup¬ 
posed to turn about the center of the rear axle as a center. 

Action of Wheels in Turning. If the wheels are supposed to 
turn through an angle, the action of the above arrangement will be 
seen. Suppose the steering gear (not shown in Fig. 316) is turned so 
as to move the steering lever AD to the new position, shown dotted 
at AD i. This movement will also move the other lever BC to a new 
position, shown dotted at BC\. It will be noted in this position that 
the angle through which the right-hand lever BC has swung is not as 















448 


GASOLINE AUTOMOBILES 


great as that through which the left-hand lever AD has moved, 
although the two levers are attached together by means of the cross- 
connection DC. 

The wheels are mounted upon the extremities of the steering 
knuckles at F and I; EG represents the left wheel, and IIJ the 
right wheel. These turn about the pivot points A and B, with 
the movement of the steering knuckles to the new positions, shown 
dotted at EiFiGiand IIiIiJi. In this position, prolongations 
of the lines through the pivot point and the center of the two 
wheels will meet the rear-axle center line prolonged at separate 
points as OP, the two lines converging slightly. This same con¬ 
vergence may be noted by prolonging the center line of the two 
wheels EiGi to Q and Hi Ji to R. This divergence means that 
the two wheels are turning on curves of different radii, and since the 
outer wheel II 1 J 1 shows a longer distance from its center line pro¬ 
longed to the rear-axle line OPM KL than does the inner wheel, 
that is, has the longer false radius, PI i being longer than OFi, it 
follows that the turning action will be correct. 

This is somewhat complicated and rather hard to follow, but 
the figure seems simple and should be examined closely, even draw¬ 
ing it out step by step, as outlined above, for the purpose of making 
the steering action clear. Laying this out for one’s self will bring 
out the reason why the steering knuckles do not move through the 
same distance and thus bring about a different movement of the 
wheels. 

Steering Levers in Front of Axle. That the final movement 
of the wheels will not be changed if the levers, Fig. 316, are laid out 
in the same way but in front of the axle will be evident by prolong¬ 
ing the levers to S and T, respectively, making the lengths AS 
and BT the same as the former lengths AD and BC. Connecting 
the two by the rod S T completes the front arrangement, which is 
seen to give the same results as the other. The choice of a front or 
rear location depends upon certain things, such as the safety of the 
cross-rod, etc., which will be brought out later on. Some machine 
manufacturers even go so far as to fit both front and rear levers to 
the same machine. 

While shifting the lever from rear to front in Fig. 316 does not 
change the result at all, in Fig. 317 it does. In this construction, 


GASOLINE AUTOMOBILES 


449 


\ 

known as the Davis, the steering levers are set in front, but taper 
inward instead of outward, so that their center lines prolonged 
meet the center line of the car prolonged at a distance from the front 
axle equal to the distance between the front and rear axles, or equal 
to the wheel base. 

In addition, the connecting rod is carried in guides placed on 
the front of the axle, so that its path of travel is always parallel to 
the front axle. Consequently, the levers must be made slotted or 
telescopic. The result of this combination of movements is an 



Fig. 317. Patented English Steering Device, Said to be Theoretically Perfect 


absolutely correct angle to both wheels for any angle of lock. This 
can be explained by a reference to the diagram. 

In Fig. 316 the prolongations of the wheel center lines, or radii of 
turning, do not strike the center line of the rear axle about which 
they are supposed to turn—at a common point, the difference being 
the amount they are out of true, viz, the distance between the points 
0 and P. If Fig. 317 be lettered to correspond with Fig. 316, the 
prolongations of the knuckle center lines At \0 and I\hP in 
Fig. 316 become the two converging lines AF\0 and hBO meeting 



























450 


GASOLINE AUTOMOBILES 


at the point 0 on the center line LMO of the rear axle prolonged. 
This is as it should be and shows the case of correct steering and 
turning. 

In this case, all four wheels are turning about the point 0, the 
two rear wheels with the radii OM and OL, and the two front wheels 
with the radii OF i and 01 i, respectively. This gives a theoretically 
correct case in which all wheels will round any curve as they should 
and not slip or slide around, damaging the tires in the process. The 
Davis type of steering gear, it may be remarked, is not in general 
use, its construction adding a number of parts to the more usual form, 
shown in Fig. 316, which gives close enough results for average use. 

Like the sliding-gear transmission, a steering gear is a form of 
mechanism which, although used on nearly all automobiles, is, from 
a theoretical and mechanical standpoint, far from what it should be. 

General Characteristics of Steering Gears. Standard Types. 
The movement or deflection of the front road wheels is obtained by 



Fig. 318. Typical Steering Gear and Connections to Front Axle 


a crosswise movement of the tie rod which links the steering-knuckle 
levers attached to the wheels. This tie rod, sometimes referred to as 
the cross-connecting rod, is actuated by the drag link GF, Fig. 318, 
which is pivotally mounted on the steering-knuckle lever L. The 
drag link has a linear movement along the frame and is parallel with it. 

The drag link is also pivotally mounted at the ball arm of the 
steering gear C, and when the drag link is moved forward or back¬ 
ward by movement of the ball arm, the tie rod is moved at right 
angles, deflecting the wheels. The drag link has a semi-rotary 
motion; that is, its upper end is turned through a part of a revolu¬ 
tion while its, lower end, to which the drag link is attached, swings 
















GASOLINE AUTOMOBILES 


451 


through a fairly large arc, according to the capacity and design of 
the steering gear. 

As the ball arm swings through its arc, the drag link attached to 
it rises and falls slightly, the movement being indicated by the dotted 
lines in Fig. 318. The partial circular motion in a vertical plane is 
converted from the rotation of the steering gear in a horizontal plane 
by several methods. The gear shown in Fig. 319 is known as the 
worm and sector type, which is illustrated in Fig. 318. 

In Fig. 319 the steering column or post CD carries a worm F 
which is in mesh with the gear E. 

Rotating the column CD in the 
direction indicated by the arrows, 
or counter-clockwise, will result 
in the worm turning in the same 
direction. The gear E will rotate 
on its horizontal shaft in a down¬ 
ward movement, as shown by the 
arrow, and as the ball arm, or 
lever, is attached to the shaft, the 
member L will move backward, 
or to the left, as shown by the 
arrow intersecting the ball. With 
the worm type the two gears are 
usually in two different planes 
at right angles to each other, one 
vertical and the other horizontal. 

This is an advantage in that it 
lends itself readily to the con¬ 
struction of a simple steering- 
gear system. Thus the post is in a vertical or modified veitical line, 
as is also the motion of the steering arm, and the consequent 
movement of the steering rod is more or less confined to a vertical 
plane. With the worm and gear this is obtained in a simple manner. 
The gearshaft is in a horizontal plane passing through the center line 
of the worm. If the worm rotates in a direction which approxi 
mates a horizontal circle around a vertical axis, the woim gear will 
turn in a vertical plane about a horizontal axis. A le\ er attached 
to the end of this shaft will, consequently, move in the desired 



.*4 


e 


Fig. 319. Worm and Partial Gear of Typical 
Steering Gear 











452 


GASOLINE AUTOMOBILES 


plane—the vertical one mentioned before—and the desired require¬ 
ments are met. 

The conversion of rotary motion in a horizontal plane to partial 
rotation in a vertical plane is shown in Fig. 320, the action here being 
slightly amplified. The steering, or hand, wheel A with spokes B is 
turned to the left, turning the steering column C (a hollow tube) in 
the direction indicated by the small arrow. D is the steering gear 
with its ball arm E. The turning of the hand wheel moves the 
ball end F and drag link backward. The front end of the drag link 
is attached to the steering knuckle M at H and turns about the 
center line KL of the steering knuckle J, the end turning through 



Fig. 320. Steering Mechanism and Front Axle of Pierce-Arrow Car 
Courtesy of Pierce-Arrow Motor Car Company, Buffalo, New York 


the arc HI. The lever M is attached to the knuckle J and turns with 
it. Its end turns through the arc OP, moving the tie rod OQ to the 
right and turning the other knuckle in the same way and direction. 
Y Y are the spring pads and ZZ the tapered roller bearings support¬ 
ing the road wheels. 

Classification. There are three general forms of steering gears: 
the worm, the bevel, and the spur. These may be subdivided, 
which might lead one to assume that there are a dozen or more 
different forms. The mechanical lever has been discarded because of 
its tendency to impart all road shocks to the driver; it is fully revers¬ 
ible at all times. Irreversibility is employed because it transmits to 







GASOLINE AUTOMOBILES 


453 



the road wheels any turning movement imparted by the driver 
without reversing or carrying back to the operator the original move¬ 
ment of the road wheels. 

Many attempts have been made to substitute another form of 
mechanism for steering gears; this consists of various rod, lever, 
chain, and spring combinations. All of these have failed, however, 
because they lacked the 
fundamental requisite of 
irreversibility. 

Aside from the many 
schemes mentioned which 
seek to avoid the use of 
the regular gear in the 
standard manner, there 
have been a number of 
unsuccessful attempts to 
avoid its use in other 
ways. Fig. 321 shows 
some of the gears which 
have been tried. At 1 is 
seen a device in which the 
rotation of a large bevel 
gear turned a small bevel 
pinion, the rotation of the 
latter serving to screw a 
long straight lever with a 
threaded inner end into or 
out of the interior of the 
threaded bevel pinion. 

In the figure, N is the 

. . . . , Fig. 321. Obsolete Forms of Worm Steering Gears 

actuating bevel turned by 

the movement of the operator’s hands, while 0 is the smaller actu¬ 
ated bevel pinion. Within this is seen the worm end S of the 
lever J, the ball at the outer end being connected to the steering 
knuckle. Since the bevel alone lost a great deal of power in friction, 
while the worm arrangement and the sliding action of the lever in 
its bearings did likewise, the total effort to turn this must have been 
enormous. At 2 is shown another form, which is the double-bevel 





































454 


GASOLINE AUTOMOBILES 


arrangement; a small bevel N attached to the steering post K turns 
the larger bevel 0, which is pivoted at the axis M about which the 
lever J attached to the segmental bevel 0 turns. 

A most peculiar arrangement is shown at 3, this being a com¬ 
bination of a worm and nut, two levers and a steering arm, as well 
as a connecting link for the two levers. Turning the hand wheel 
turns the worm, which moves the nut up or down. Since the nut 
is connected by means of the link to the lever, the motion of the 
nut up and down is transmitted to the short lever; this, in turn, 
moves the long-arm, or steering, lever. In the figure, K is the steering 
post, N the worm, 0 the nut, P the connecting link pivoted at the 
two ends T and S, Q the short-arm lever, and J the steering lever, 
the two latter being integral and pivoted at the point R. At 4 
is shown a combination of a double internal worm with a rack and 
gear. In this, the turning movement of the inner worm causes the 
outer worm to travel up and down. Upon the exterior of this outer 
worm is cut a rack which is meshed with the gear, its up and down 
movements turning the gear around and thus effecting the steering, 
the steering lever being attached to the gear. N is the internal 
worm, 0 the external worm with the exterior rack, P the gear which 
meshes with it and carries the lever J as a part of it. At 5 is shown 
a combination of a double worm with a double ball and socket 
arrangement. The turning of the outer worm N\ causes the inner 
worm N to rise and fall, the lower end of this carrying a ball-and- 
socket joint 0, the end of the ball being formed integral with the 
steering lever J, which also has a ball and socket attachment at the 
other end. At 6 is shown a steering gear which was tried and dis¬ 
carded, but which is now coming to the fore and bids fair to oust 
many other forms of gear. It is variously called a globular worm, 
helicoidal worm, or Hindley worm, the worm forming a curve closely 
approximating the curve of the gear with which it is to mesh. This 
gives a greater number of teeth in mesh at any one time, spreading 
the wear over a larger surface and thus lengthening the life as well as 
accuracy of the steering gear. 

Spur and Bevel Types. The spur- and bevel-toothed construc¬ 
tion of gears may be reversible, and these types are to be found on 
low-priced cars, as the cost of cutting the gears is small. The spur 
gears have straight teeth, the edges, or sides, of the teeth being straight 


GASOLINE AUTOMOBILES 


455 



cind parallel \\ ltli the axis of the shaft on which the gear turns. In 
be\ el geai s the teeth taper toward a point and are inclined to the 
axis of the shaft. Another construction is the spiral gear. Both 
types may be made reversible and irreversible as desired. 

Worm-Gear Types. With a very few exceptions, automobile 
engineers favor the worm type of steering gear, and it will be found 
on the highest priced ears. It has the advantage of being irreversible 
and is utilized in several forms. In the worm class of gears, some types 
are closely related, while others vary widely. For example, the com¬ 
plete sector and gear type 
differ only in that the wheel 
operated by the worm makes 
a complete circle or part of 
a circle. The full gear can 
be turned through 90 degrees 
and replaced on the shaft 
without presenting a new 
surface to the worm. Some 
hold that the worm must be 
subject to some wear, espe¬ 
cially where it is most used. 

They contend that turning 
over the pinion brings new 
teeth to engage with the 
worm and that these teeth 
will not mesh properly when 
turned at an angle of from 
20 to 30 degrees. 

Worm and Partial Gear. 

Fig. 322 illustrates a gear of the worm and partial gear type. 
Advantages claimed for the design are durability, ease of action, 
and adjustability to wear. The parts are accurately cut and hard¬ 
ened, and the worm is provided with a ball thrust on either side. 
With this type, the teeth, which are in the middle of the sector 
and in mesh, perform the greatest work when the car is driven in 
a straight line and are most susceptible to wear. To compensate 
for this wear, the center teeth are cut on a slightly less pitch radius 
so that lost motion may be eliminated without affecting the upper 


Fig. 322. Worm and Partial Gear Type of 
Steering Gear 





456 


GASOLINE AUTOMOBILES 


and lower teeth of the sector and to prevent binding when turning 
at right angles. In the illustration, A is the steering column to 
which the worm C is secured, D is the sector in mesh with the 
worm, E is the ball arm, or lever, B the gear housing, F the spark 
and throttle bevel gears and levers, and G the lubricant plug. 

Adjustment. Two principal adjustments are provided. End 
play of the worm is eliminated by loosening the'jamb nuts and lock 
screws on the column housing. Displacing the oil plug G will dis¬ 
close an adjusting collar which is set with a screwdriver. Adjust 
collar until all play is eliminated, but the worm must turn easily. 
The lock screws, above referred to, are so located in the gear housing 
that when one is directly over a slot in the adjusting collar the other 
is between two slots. Consequently, after adjusting the collar it is 
essential that the proper screw be selected for locking the adjustment. 
Both locking members must be prevented from turning, by using the 
nuts. Wear of the teeth of the worm and sector may be eliminated 
by means of an eccentric bushing, which, when turned, moves the 

sector into a closer relation with the worm. This is accomplished by 

% 

removing a locking screw at the left of the ball arm and moving 
the arm, which turns the eccentric bushing. In case of extreme wear, 
it may be necessary to displace the ball arm and set the locking-screw 
section in a different position on the end of the hexagonal end of the 
eccentric bushing so as to bring the arm in such a position that it can 
be locked by the screw. End play of the sector shaft is eliminated 
by removing a locking arm and turning an adjusting screw in, after 
which the arm and lock screw are replaced and both set up tight. 

Worm and Full Gear. A full gear and worm type of steering 
gear is shown in Fig. 323, with the gear cover removed. This type 
is irreversible, and the advantage claimed for it is that it can be easily 
removed and so readjusted that an unworn section of the gear may 
be brought into contact with the worm. This is a simple form, and 
it is possible to replace a worn gear with a new one, as the gears are 
not expensive. 

Fig. 324 shows a much more complicated form of worm and full 
gear in which the inventor has attempted to gain something by 
the use of a double steering gear, that is, two complete sets of worms 
and gears set opposing one another, the gears being made to mesh 
with each other just like a pair of spur gears. Since the lever can 



GASOLINE AUTOMOBILES 457 

be attached to but one of the turning gears, the other gear with 
its actuating worm is useless. The inventor doubtless intended 
the two worms to oppose each other and thus be self-sustaining as 
to thrust, but such would not be the case, the actual thrust being in 
opposite directions in the two cases of the upper and lower worms, 
the total thus being double the usual amount. 

Adjustment. The part most subject to wear is that section of 
the gear which meshes with the worm when the front wheels are 
traveling in approximately a straight line. Because of this wear, the 
teeth of the wheel are subject to deterioration. Usually the adjust- 


Fig. 323. Typical Worm and Full Gear Steering Device 

ment for the wear is made by bringing the worm into a closer relation¬ 
ship with the gear by using the eccentric bushings which support the 
worm shaft. This adjustment is practical when the lost motion is 
due to poor adjustment rather than to wear of the teeth. With the 
majority of types, it is possible to displace the steering arms, move 
the steering wheel about half a turn, then replace the worm wheel so 
that an unworn section opposite the worn teeth will be brought into 
engagement with a comparatively unworn portion of the worm 
proper. The eccentric bushings in this case can be utilized to obtain 
a correct meshing of the worm and gear teeth. End play of the worm 


458 


GASOLINE AUTOMOBILES 


can be removed by adjusting the ball thrust bearings on either side 
of the worm. Sometimes these bearings become dry, or the lubri¬ 
cant becomes gummy, causing the shaft to turn hard. Wear of plain 
bushings in the steering-gear case is responsible for lost motion; the 
remedy is to replace the bushings with new members. 

Worm and Nut. Next to the worm and gear, either full or 
partial, the form of steering gear most used is the worm and nut, 
which is made in several different combinations. Thus, the nut may 
operate the steering lever directly through the medium of a secondary 
lever, or it may actuate a block, which, in turn, moves either the 
lever direct or the secondary lever. In Fig. 325 another form of 


Fig. 324. Double Worm and Gear 
Steering Device 




Fig. 325. Worm and Nut Steering 
Device 


the worm and nut variety is shown. This has a nut which the turning 
of the worm moves up and down but which is split, the two halves 
being bolted together. A spherical seat is formed in the two 
halves of the split nut into which a ball-end lever is set, the bolt 
serving to clamp the two pieces together and hold the lever there. 

This is the end of the secondary lever, which is connected by 
means of another lever to the steering lever itself. In the figure, A 
is the worm, B and B l the two parts of the nut, C the clamping 
bolt, and D the hinge at the other end. E and E l represent the 
spherical seats for the ball end of the other lever. 



GASOLINE AUTOMOBILES 


459 


Having the nut in two widely separated parts reduces the wear 
on each, since the bearing surface is spread out more than would be 



min 


Hear V/ew 


3/de View 


Fig. 326. Steering Gear Used on Heavy Manhattan Trucks 


1 1 

1 • 

.•TJf 

i i 

i: 

i i 

ij 

i i 
i i 
• i 
i • 


the case with an uncut nut. In addition, the split nut allows the 
changing of the ball-end lever at any and all times. 
























































































































460 


GASOLINE AUTOMOBILES 




Fig. 327. Sectional Details of Steering 
Gear of Winton Cars 

Winton Motor Car Company, 
Cleveland, Ohio 


In Fig. 326 is shown a form of 
worm and nut steering gear which is 
used on very heavy trucks and com- 
merical cars. In this gear, the double 
worm is used; the inner worm carries, 
at its lower end, a block which is piv¬ 
oted in a combination lever and shaft, 
to which the steering arm is attached. 
In the figure, A is the hand wheel 
turning the rod B within the steering- 
post tube C. This rod is driven into 
and keyed at its lower end to a mem¬ 
ber D which has internal worm 
threads. Another piember E has a 
circular upper end on which are worm 
threads, while its lower end is slotted. 
The worm at the upper end meshes 
with the internal worm threads in 
piece D, while the lower slotted end 
carries, between the two arms of the 
slot, a rectangular block F. This 
block is hardened and ground all over 
and is fastened to the forked end of 
piece E by means of the hardened and 
ground pin G. This pin also passes 
through the arm II of the shaft to 
which the steering arm is attached. 
The steering arm is free to rotate 
about the center. This rotation moves 
the steering lever L in the arm of v 
circle. 

The steering action is as follows: 
Turning the hand wheel turns the 
outer worm. This worm cannot move, 
so the inner worm is forced to move 
up or down, as the case may be, and 
moves the block with the pin through 
it, which, being fixed in the arm 


















































































GASOLINE AUTOMOBILES 


461 


extension of the shaft, must turn the shaft. To this arm is attached 
the steering lever, so the latter must move. Although a rather com¬ 
plicated gear to explain and also to make, this gear, when finished, is 
an excellent one, and has been used for five or six years on heavy 
trucks with excellent results. 

The Winton steering gear, Fig. 327, is not decidedly different 
from the one just shown, as will be noted by a close inspection of the 
parts. A is the internal worm, which is turned by the hand wheel, 
while engaging this worm are the block B and pin C, the block being 
partly cut away to show the engaging gear teeth. This block moves 
the jaw arm of the steering lever D. This jaw is not complete in 
this gear, but is cut away to save weight. The jaw arm, too, is con¬ 
nected directly with the steering lever, the jaw, arm, and shaft making 
one piece. The light work to which this was put made possible the 
economy in the number of pieces and in the weight of each. As 
before, turning the hand wheel turns the worm, which, in turn, moves 
the block and pin up and down and thus moves the jaw arm, which 
moves the steering lever. 

Adjustment. The adjustment for lost motion in the worm and 
split-nut type of gear is generally made by loosening a cap screw on 
the column and screwing down an adjusting nut which has a right- 
hand thread. This adjusting nut acts directly on the thrust bearing, 
forcing the screw and half nuts, which slide, against the yoke rollers. 
In making the adjustment to a gear of this type, it is advisable to 
turn the road wheels to the extreme angle position, because the gear 
is the least worn at this point, and if it is adjusted only enough to 
take up the play when in this position, there will be danger of binding. 
Sometimes, when the adjustment is made with the road wheels straight, 
the gear will bind at the extreme positions. 

Worm and Worm. In the worm and worm form of steering gear 
there is a worm within a worm, not wholly unlike the ones just 
described. Fig. 328 shows an example of this, which has a worm C 
attached to the steering rod H, which is turned by the steering wheel 
A. Within and without this are worm threads, an external worm 
B meshing with the internal worm on the inside of C , while an internal 
worm D meshes with the external worm on C . The action of turn¬ 
ing the hand wheel, then, moves one of these upward and the other 
downward. 


462 


GASOLINE AUTOMOBILES 


The lower end Bi of the inner worm member presses against 
a hardened end of the steering-lever arm E, while the lower end D x 
of the outer worm member presses against the other hardened end 
Ei of the same piece. There is no lost motion, or play, in the gear; 
when the hand wheel is turned, one worm rises and the other falls, 
as just described; the piece E will let one end rise and the other fall, 
as it is acted upon by the lower extremities of the two moving worms. 
This piece is pivoted at F and carries at its outer end the steering 
lever G, which thus moves in the customary manner. Within the 
steering post are the spark and throttle tube and rod I and J, which 



Fig. 328. Section of Gemmer Steering Gear 
Courtesy of Gemmer Gear Company, Detroit, Michigan 


carry right through the whole gear and out at the bottom, where 
the spark and throttle-actuating levers are attached. 

Adjustment. The adjustment of the worm and worm type, an 
example of which is illustrated in Fig. 328, is generally effected by a 
nut located at the upper end of the gear housing. This nut is pro¬ 
vided with flats to accommodate a wrench hold. The end of the 
worm-wheel shaft is squared, and to this square the steering-lever 
arms are attached by means of a pinch clamp and bolt. 

Bevel Pinion and Sector. Among the other types of steering 
gears is that of the bevel pinion and sector, shown in Fig. 329. The 






















GASOLINE AUTOMOBILES 


463 

f 

bevel pinion moves the bevel-gear sector back and forth as it is turned, 
this motion being transferred to the steering arm attached on the 
same shaft to which the bevel sector is secured. This type of gear is 
said to be effective, but it is not irreversible, and shocks to the road 
wheels may be imparted to the steering wheel and move it. 



Fig. 329. Bevel Pinion and Sector Type of Steering Gear 
Courtesy of Reo Motor Car Company, Lansing, Michigan 


Adjustment. The bevel and sector gear has two adjustments. 
The pinion may be moved up or down, as required, by unlocking the 
clamp bolts (one of which is shown at D) which permits the moving of 
the entire steering column up or down so as to obtain the proper 
















































































464 


GASOLINE AUTOMOBILES 


relative position to the pinion and its sector. The position of the 
sector endwise may be adjusted by the block member A, which bears 
against a roller guide, forcing the sector into mesh more or less closely 
with the pinion. The spring E is provided to prevent rattling, and 
the screw H is a guide for the plunger and should not be disturbed 
in making the adjustment. 

Hindley Worm Gear. There are a number of things about the 
Hindley type of worm which make it an excellent one to use for 
steering gears. A realization of this advantage is bringing about a 
greatly increased use of this form; so it will be appropriate and timely 

to look into its form, con¬ 
struction, and advantages. 

The question of what 
makes the Hindley different 
from other worms naturally 
arises. The ordinary worm 
has the same diameter from 
one end to the other, the 
blank before the cutting of 
the teeth resembling a sec¬ 
tion of a cylinder. The Hind¬ 
ley, on the other hand, is not 
of uniform diameter, but has 
a smaller center diameter and 
enlarged ends. This gives it 
a waist, or hour-glass, shape. 

An illustration will make this clear. Fig. 330 shows at A how 
the Hindley shape is generated and at B a finished gear, revealing 
plainly the reduced center diameter. In the upper figure, EE is the 
center line, or axis, of the worm, and 0 the center of the gear which 
is to mesh with it. CD is a circular arc struck from 0 as a center. 
If, on this curve CD, equal spaces be struck off, using a distance equal 
to the pitch of a single-threaded worm or the lead of a multiple- 
threaded one, as at F, and radial lines be drawn from the center 0 
to these points, these lines will be normal to the surface of the worm at 
those points; in short, the worm must pass through them, as roughly 
sketched in the figure. In the lower part B, of the figure, is illustrated 
a worm made on this principle, ready to be put into position. 




Fig. 330. Details of the Hindley Worm 




























































GASOLINE AUTOMOBILES 


465 


This form of worm is used for the double reason of presenting 
more wearing surface—since it has at least three teeth in contact 
at any one time, as compared with one or at most two in the 
ordinary worm—and greater resistance to reversibility. The worm 
is used for steering gears because it is partly or wholly irreversible, 
its motion being a sliding one; nevertheless, all worms may be 
so cut as to be either wholly or not at all reversible. The sliding 
motion of the two parts in contact, as opposed to the rolling motion 
in the case of other mechanical movements of a similar nature, is 
greatly increased if there are three teeth in contact instead of the 
more usual one. If the friction of sliding be increased, the amount 
of reversibility will be decreased in the same proportion, for the added 
sliding friction will increase the natural reluctance of the worm to 
transmit power backwards. So much is this the case that it pays 
to use the Hindley form, despite its greatly increased cost of cutting. 

Ford Steering Gear. The steering mechanism of the Ford car— 
a patented construction—differs radically from the conventional 
types in that its hand wheel does not directly rotate, or turn, the steer¬ 
ing column or rod, but it imparts the necessary turning movement 
through the gearing and the use of a small shaft to which the hand 
wheel is attached. A phantom view of the gearing is shown in Fig. 331. 

The steering column with its short shaft and drive pinion is 
enclosed in a tube or housing which is set at an angle and bolted to 
the dash. The housing does not extend the entire length of the 
column, as the lower end of it is mounted in a bracket that is rigidly 
bolted to the frame. The steering-gear post, or column, has a tri¬ 
angular flange at right angles to the rod, and each point of the flange 
has an integral stub, or pin, carrying a small spur pinion. The center 
of the rod is drilled and bushed to take a small shaft to which a fourth 
pinion, or drive pinion, is keyed. The upper part of the housing is 
shaped so as to provide a gear case, and the inner periphery of this 
case is cut to obtain spur teeth or, in other words, an internal ring 
gear. This gear is stationary. 

The hand wheel is attached to the short shaft, and its drive 
pinion is held in place by a brass cover of the internal gear case. As 
the drive pinion of the shaft is in mesh with the three pinions mounted 
on the stubs of the steering column proper, and these three pinions 
are in mesh with the internal ring gear, any movement of the hand 


466 


GASOLINE AUTOMOBILES 


wheel will rotate the drive pinion on its shaft. This movement will 
cause the three spur pinions to rotate in an opposite direction against 
the internal gear, thus reducing the movement of the steering column 
as compared to that of the hand wheel. The three spur pinions 
compensate for any pressure of the drag link and the tie rod. 

The operation of the Ford steering-gear mechanism explains the 
basic principle of the operation of the hand wheel; that is why the 
wheel is turned in the same direction that the driver desires the car to 



go. If the hand wheel is revolved from left to right, for example, the 
movement causes the three pinions mounted on the pins of the steering 
column to rotate from right to left; the pinions rotating against the 
stationary internal gear turn the steering rod in the same direction 
taken by the three pinions. The column swings an arm attached to 
it from right to left, and, as the rod is secured to this arm, it moves 
in the same direction, swinging the front road wheels so that they 
move from left to right, and to a degree that will correspond with the 
turning, or movement, of the hand wheel. It should be understood 
that the movement from left to right refers to the front half of the- 
road wheels. If the driver desires to direct the vehicle to the left, 
the wheel is turned to the left. 








































GASOLINE AUTOMOBILES 


467 


The drag link of the Ford steering gear differs from conventional 
designs in that it is at right angles to the frame and is practically 
two-thirds the length of the tie rod. The end of the steering column 
is provided with an arm carrying a ball, and the drag link, or steering- 
gear connecting rod, as it is listed by Ford, has a ball-socket 
cap which fits over the ball of the steering rod. The drag link also 
has a ball socket at its other end, which fits over a ball arm on the tie 
rod. The tie rod, called the spindle connecting rod because it con¬ 
nects the spindles, is provided with yokes at either end, and these 
yokes are pivotally connected to the spindles by a bolt passing 
through them and 
through an eye in the 
spindle. The Ford drag 
link differs from others 
in usual practice in that 
it moves to the right and 
left, while those used on 
other cars move forward 
and backward. No pro¬ 
vision is made with the 
Ford drag link for absorb¬ 
ing shocks or for auto¬ 
matically compensating 
for wear as usually is the 
case with the conven¬ 
tional type of drag link. 

Semi=Reversible Gear. The steering gear used on commercial 
cars, particularly trucks ranging from 3- to 7-ton capacity, must not 
only be capable of operation with a minimum effort, but it must 
absorb a great many of the minor shocks and a per cent of the larger 
shocks. The semi-irreversible type is most favored because of the 
above-named reasons. The design shown in Fig. 332 is of the screw 
and nut type. The nut is a solid piece, completely enveloping the 
screw, and the threads of the screw are in constant and complete 
engagement with the threads in the nut. The screw has a rotary 
motion and the nut has a longitudinal motion. The means of trans¬ 
mitting this longitudinal motion of the nut to the rotary motion of 
the steering arm is by circular discs at the lower end of the nut. 







Fig. 332. Screw and Nut Gear Used on Trucks 

























468 


GASOLINE AUTOMOBILES 


These discs present constant bearing surfaces to the recesses in the 
nut, and are provided with slots into which the projecting levers from 
the rocker shaft fit. The screw pulls the nut up or down in the 
housing, and there is no tendency for this nut to be moved sideways. 




The levers projecting from the rocker shaft into the swivels which 
rotate in the lower part of the nut are in direct line with the screw, 
so that the push and pull of the nut is in a straight line. 

Removing Steering Gear. To-disassemble the majority of 
steering gears it is necessary to remove the unit. With the type shown 


































































































































GASOLINE AUTOMOBILES 


469 


in F ig. 333, which is a semi-irreversible worm and gear, the removal 
may be accomplished by displacing the control levers at the top of 
the column and dropping the unit down through the frame. The 
adjustment of this type for end play is made by loosening the locking 
nut A and turning down the nut B until the play is eliminated. 

STEERING=GEAR ASSEMBLY TROUBLES AND REPAIRS 

Lost Motion and Backlash. Lost motion of the steering wheel 
does not always indicate that the steering gear is at fault, for wear in 
the steering-gear assembly usually takes place first in the clevis pins, 
yokes, and connections of the drag link. The spindles, spindle bolts, 
and wheel bearings are factors. Despite the fact that the front road 
wheels are deflected but a few degrees the spindles, bolts, or bushings 
may be worn, as these parts are subject to radial and thrust loads. 
The spindle bolt, which does not move, tends to wear oval; adding to 
this tendency the wear of the spindle bushings, one has considerable 
lost motion to contend with. Wear of the wheel bearings contributes 
to the apparent lost motion of the steering gear as do the connections 
of the drag link. Taking all of these factors into consideration, and 
allowing but a small fraction of an inch for play of each worn part, 
the sum total may result in considerable movement of the hand wheel 
before the road wheels are deflected. 

Lost Motion in Wheel. While there should be a certain amount 
of movement to the hand wheel before it actuates the road wheels, 
the lost motion, as a rule, does not exceed J or f inch when the gear 
is new. This amount is essential as without some free movement the 
steering of the vehicle would be tiresome. Wheels may be keyed or 
pinned to the column. When play exists as the result of a worn key, 
pin, or slots, the remedy is to re-cut the seats and make and fit a new 
key or pin. With some types of wheels the use of a wheel puller will 
be necessary to displace them. Another, cause of lost motion, when 
the wheel is tight and linkage free from play, is a loose key retaining the 
worm or gears of the steering gear proper. A simple test of the hand 
wheel is to hold the tube, or post, securely and move the hand wheel. 
The amount of play in the drag link can be ascertained by grasping 
it about midway and trying to move it backward or forward or in the 
normal direction of travel. Hold the ball arm of the steering gear 
when making this test. 


470 


GASOLINE AUTOMOBILES 


The amount of backlash present in the irreversible and semi- 
irreversible types of steering gears may be determined by disconnect¬ 
ing the drag link, grasping the ball arm, and moving it up and down 
and back and forth. Worn bushings in the steering-gear case are 
frequently the cause of movement of the column as a whole. Another 
component that should not be overlooked in the search for the cause 
of lost motion is the ball arm. Movement of this member on its 
shaft can usually be eliminated by tightening the nut. 

STEERING WHEELS 

Different Forms of Hand Wheels. Wood Rim. A variety of 
material is utilized in the construction of the wheel, which has super¬ 



seded the lever or tiller. The section or sections of the wheel or rim 
are circular, oval, or elliptical; the oval, or ellipse, is turned upward. 
The strength of the wheel varies according to the material used and 
the process of assembly. The all wood wheel has not the strength of 
a built-up wheel with a metal core, but it is simpler and cheaper to 
manufacture. With the exception of the molded rubber type of 
rim, the majority of the wheels, particularly those fitted to high- 
grade cars, are built-up. Mahogany, Circassian walnut, and black 

i ' 

walnut are the materials favored. The wood is cut to short sectors 
pf an annular ring of about 2 inches in width and so glued together 
as to eliminate joints. 

The method of attaching the rim to the spokes of the wheel 
spider is by screws, and this method is illustrated in Fig. 334. A 
































GASOLINE AUTOMOBILES 


471 


indicates the wood member, B the arms, or spokes, which have a 
boss through which the screw C passes into the wood. The hub of 
the spider D is attached to the steering post by two keys E. 

Metal Core with Wood Covering. When the wheel design is made 
up of a metal core the ring is cast on the spider or integral with it. 
Coverings of wood concealing the ring are used, although with some 
types, a section of the ring may be noted. This type of wheel pos¬ 
sesses great strength and the wood veneers can be secured at more 
frequent intervals than in the design previously described. 

Different Wheels for Commercial Use. Truck Types. For the 
light delivery wagon, taxicab, and similar cars, no difference in the 
steering wheel is made, but when it comes to the heavier service, there 
is a need for a heavier wheel. This does not mean a heavier rim 
only, but a heavier, more rugged gear all the way through. The 
weight on the front wheels of a heavy truck is very great, and 
the tires, which are of solid rubber, may have frictional contact with 
the pavement of several inches in width. All this combines to make 
turning the vehicle from the driver’s seat more difficult. 

For this reason the driver must have a greater leverage, which 
means a larger diameter of the wheel. Then, too, the rim should be 
bigger in section in order to withstand the harder use of commercial 
service, and to provide for the large hands of the operators. Greater 
strain upon the rim of the wheel, on attempting to turn heavier 
weights with it, means that the rim must be fastened to the spider more 
securely. This means more arms, the four generally used for pleasure 
cars being increased to five for trucks. While this helps a great 
deal, since it provides five screws instead of four, it is not sufficient, 
and most of the big trucks today are equipped with steering wheels 
in which the rim is built over a central metal rim of the spider. 

Pleasure-Car Types. Usual pleasure-car practice varies from 
14-inch up to 16-inch wheels, while commercial car sizes begin at 16- 
inch and run up to 18-inch wheels on light trucks, and as high as 20- 
and 22-inch wheels on heavy trucks. Rim sizes vary considerably, a 
favorite for touring cars being an oval with from f- to J-inch vertical 
height and a length of about 1 re to 1A inches. These figures have no 
connection with commercial work, the smallest being 1 inch and on 
up to lg inches in height, with the long diameters varying from 1| up 
to If inches. For speed work, racing, and the like, it is usual practice 


472 


GASOLINE AUTOMOBILES 


for the operator to wind the surface of the wheel with string, this 
giving a rough surface upon which the hands will not slip. This is 
practiced, too, by many truck drivers, who claim that the strains of 
steering the big vehicle are not felt as much when the wheel is thus 
wound. 

To preserve the nice appearance of the steering wheel and still 



Fig. 335. Molded Rubber Steering Rim on S.G.V. Car 
Courtesy of S.G.V. Company, Newark, New Jersey 

give the roughened surface to which the hands will cling easily, even 
in wet weather, many manufacturers are making a wheel of molded 
rubber, the use of this material allowing the formation of the wheel 
in any desired section, as is seen in Fig. 335. As a concession to 
appearances, these wheels are usually made with a plain upper surface; 
the lower or under surface, however, being made in a series of depres- 







GASOLINE AUTOMOBILES 473 

sions and humps, between which the fingers find a good resting place. 
This gives a good grip, as the under side of the wheel seldom gets wet. 

Folding Steering If heels. Although tilting steering wheels were 
introduced several years ago, they did not meet with favor until the 
Cadillac adopted them as standard equipment. The wheel, which is 
18 inches in diameter and has an aluminum spider, is hinged to drop 
downward, a design facilitating entrance and exit at either side of the 
car and making it possible to attain the driver’s seat without squeez- 


Fig. 336. Hinge Type of Steering Wheel Used on Cadillac 

ing. The Cadillac wheel is shown in Fig. 336, while that used on the 
King car, illustrated in Fig. 337, is of the tilting type. To operate 
the design, the wheel is turned until the wheel spider arm carrying 
the release button is convenient to the thumb of the right hand. 
The button is pushed to the right, and, by using both hands, the 
wheel is pushed forward and upward. The Herff type, shown in 
Fig. 338, is of the true hinged form; the rim is thrown up and out of 
the way, that is, the rim only, as the quadrant carrying the spark and 












474 


GASOLINE AUTOMOBILES 



Fig. 337. 


Tilting Steering Wheel on the 
King Car 


throttle levers remains. There are several other types marketed, but 
their working principles are similar. 

Throttle and Spark Levers. In the usual case, the arms of 

the steering wheel have the 
quadrant for the spark and throt¬ 
tle levers fastened to them. The 
levers are operated within the 
space inside of the rim of wood 
and above the spider of metal; 
the latter is usually at a lower 
level by several inches, as shown 
in the figure. In Fig. 334, how¬ 
ever, the quadrant is not carried 
by the spider arms, but on a sep¬ 
arate framework G, or spider of 
its own, up above the hub of the 
wheel. Over this frame¬ 
work the spark and throt¬ 
tle levers II and I work, 
serrations of teeth in the 
quadrant preventing 
the levers from moving, 
except when they are 
sprung off by the pressure 
of the fingers operating 
them. In some cases, 
these teeth are done away 
with and friction surfaces 
are substituted; springs 
holding the contact sur¬ 
faces together are so light as not to interfere with the moving of 
the levers by hand. 



Fig. 338. Herff-Brooks Folding Steering Wheel 


STEERING ROD, OR DRAG LINK 

Operation. By the steering rod, or drag link, is meant the 
member connecting the ball arm, or lever, of the steering gear to 
the lever attached to the steering knuckle. This is clearly illustrated 
in Fig. 339. The steering gear is marked D, the steering arm pro- 























GASOLINE AUTOMOBILES 


475 



jecting down from it C, while the steering rod which connects the 
lower end of the arm with the lever on the knuckle is marked AB. 
F is the knuckle pivoted in the axle, which carries the two-end lever 
E, one arm of which has the steering rod attached to it at B, while 
the other carries the cross-connecting rod joining the two knuckles 
together. ‘Since the pivot point is fixed, any movement imparted to 
the knuckle must result in its swinging about the pivot point and 
carrying the wheels with it. 

This movement is imparted by the steering rod to the end B 
of the arm E. The steering rod itself simply 
connects with the steering lever C, swinging 
back and forth in a vertical plane with the 
steering knuckle F, which swings around and 
back in a horizontal plane, and imparts the 
movement of the lever to the knuckle. Since 
the end of the steering lever rises and falls and 
the end of the lever on the knuckle maintains 


Fig. 339. Typical Steering Arrangement on Pleasure Car 


a constant level, although moving in a circle, the rod must have a 
universal joint at one end. This is really a necessity from two points 
of view: to allow the rear end to move up and down vertically while 
the front end swings around in a circle; and also to allow the front 
end to swing in a circle set in one horizontal plane, while the real end 
remains stationary or practically so in that plane. In short, the two 
ends move continuously, each in its own plane, but the two 
planes never coincide—the one is always vertical, while the othei 
always stays horizontal. This necessitates at least one universal 
joint. Many makers play on the safe side, and lower the cost of 












476 


GASOLINE AUTOMOBILES 


production by making the two ends alike—a universal joint on 
each one. 

Types of Construction. A glance at the construction shown in 
Fig. 340, and also in Fig. 341, shows a steering lever made with 
a ball end, or partial ball end, upon which the steering rod is 
hung. In this, the partial ball is formed in the center of a bar, the 
inner end of which is threaded and screwed into the steering arm, 
with a nut on the outside to prevent its backing out. The ball 
itself is made separately and slid on over the rounded end of the 
shaft, or axis. After this a sleeve is put on, followed by a nut which 
holds the sleeve up tight against the ball. The function of the sleeve 
is to give the spherical end of the rod plenty of play in a sidewise 

direction. This is a cheap form of con¬ 
struction, but could have been made in 
one piece had it been desirable or neces¬ 
sary to do so. Such a form has a metal- 
to-metal contact, which is hard upon both 
ball and socket, necessitating frequent and 
costly replacements. These replacements 
are obviated by backing the ball socket 
up with a spring or springs, as is shown 
in Fig. 341. This form of construction 
is now quite generally used; the socket of 
the ball in the inner end of the rod is set 
inside of a sleeve with a spring on each 
side of it. These springs not only take up the road shocks but the 
wear as well, the shoulder against which they rest being adjustable. 
In this figure, J is the lower end of the steering lever with the ball 
end. This lever is mounted in the ball socket G. A is the body of 
the steering rod, which is expanded at the end to a larger diameter, 
this being designated in the figure as B. Within this expanded 
portion, the sleeve E at one end acts as a shoulder for the spring F. 

At the other end, the outside of the sleeve is threaded to receive 
the collar C with the hexagon end K. Within this, a second spring 
L holds the socket up to its position. The location of the collar C 
determines the tension of the spring L, and this is locked in its 
position by the screw V. Should there be wear, which necessitates 
the moving of the ball toward the open, or left, end, the whole thing 



Fig. 340. Steering Lever with 
Ball End 






























GASOLINE AUTOMOBILES 


477 


is disassembled and a longer sleeve inserted in place of the one shown 
at E. On the other hand, ordinary wear is compensated for by 
taking up on the collar C, first loosening the lock screw V. 

In b ig. 342, a rod is shown assembled at the top and disassembled 
into its components at the bottom. The two ends differ, one being 



but a simple yoke with a plain bolt through it, marked D. The 
other, however, is a ball end with an adjustment and with springs 
to take up shocks. 

All these parts are marked in the figure and may be located by 
letter. The body of the rod is marked A, the expanded end B, which 
has a groove II cut in it. Into the inner end of this groove is fitted, 
first, the spring F; second, the two halves of the ball socket G; and 



Fig. 342. Cross-Connecting Rod Assembled and in Parts 


third, another spring. The sleeve E closes the outer end, and over 
the exterior is screwed the adjusting nut C. The nut and sleeve are 
held in place by the locking pin V, which passes through the 
outer nut, the shell end of the rod, and the inner spacing sleeve, the 
ends being riveted over to hold it in place. This form limits the adjust- 





























































478 


GASOLINE AUTOMOBILES 




ment to a full half turn of the nut, while the pin would soon need 
replacement if much adjusting were done, as some of its length would 
be lost each time it was riveted over because of the chipping away 
to allow it to be taken out. 

Cross=Connecting, or Tie, Rods. The object of the cross¬ 
connecting, or tie, rod is to connect the right- and left-hand steering 
knuckles so that the road wheels will be turned alike. The general 
practice is to place the rod back of the front axle, a location avoiding 
the possibility of damage if an obstruction in the road is encountered, 
but in some instances the tie rod is placed in front, as in Fig. 339. 


Fig. 343. Finished S.G.V. Chrome Nickel-Steel Steering Knuckle and the Same 

before Machining 


Fig. 344. Left Steering Knuckle of S.G.V. Car before and after Machining 

The tie rod is made adjustable to compensate for any change 
that may be necessary to preserve the alignment of the wheels, and, 
generally, the rod is adjustable at either end. The yoke ends of the 
rods are made adjustable, screwing on or into the rod proper and 
secured by lock nuts or other suitable fasteners. The adjustment is 
easily made. Decreasing the length of the rod increases the gather, 
or distance, between the forward section of the front wheels, while 
increasing it causes the wheels to toe in. This applies to the tie rod 
behind the axle. 


GASOLINE AUTOMOBILES 


479 


Function and Shape of Steering Knuckles. The steering knuckles 
serve as a pivot for the road wheels, enabling them to move in a hori¬ 
zontal plane. The design of the knuckle depends upon the axle, and 
the pair used on a car are different as one has a lever for carrying the 
drag link. Both have integral spindles to which the tie rod is attached. 
Figs. 343 and 344 illustrate the difference between the knuckles. 


Fig. 345. Packard Steering Gear Parts 

Fig. 343 shows a right knuckle, forged from a blank of chrome nickel 
steel, while the one at its side is the finished part. A is the place 
for the outer wheel bearing, B the position of the inner bearing, C the 
hole for the pivot, or knuckle, pin, D the upturned steering arm, and 
E the arm to which the tie rod is attached. Fig. 344 is an example 
of a left steering knuckle of the same pair, both before and after 
machining. The letters in Fig. 343 apply to this knuckle. 



I 


480 


GASOLINE AUTOMOBILES 


Lubrication of Steering=Gear Assembly. The proper lubrication 

of the steering-gear assembly adds to its life, but this work is not, as 
a rule, thorough. The steering gear proper should be packed with 
grease, the ball and socket joints of the drag link and steering-arm 
lever with a light grease; the clevis pins also should be lubricated. 
The steering-knuckle pins are provided with either grease or oil cups. 

A point generally overlooked in the lubrication of the steering 
gear is the steering-post spark shaft and throttle-sector anchor tube, 
shown in the illustration at Fig. 345, which is of interest in that 
it illustrates the assembly of the Packard car. The post carries 

the control-box unit. The 
spark shaft and throttle tube 
frequently lack lubricant and 
should be cleaned and coated 
with a graphite grease before 
replacing when the gear is 
being reassembled. The lower 
extremity of the spark and 
throttle members carry levers 
or small bevel sectors which 
operate the linkage of the igni¬ 
tion apparatus and carburetor. 
Clamping screws are generally 
used to secure these parts. 

SPECIAL TYPES OF DRIVE 

Front=Wheel Drive. In 

the conventional type of 
pleasure motor car, the energy 
of the engine is applied to the rear wheels which propel the car, the 
drive being a pushing one. A pleasure car, or rather a racing machine, 
with a front-wheel drive—which is a pull, and held by some to be more 
economical—was brought out several years ago but not marketed. 
During the latter part of 1916, a company was formed to market an 
eight-cylinder pleasure vehicle, utilizing a front-wheel drive and steer 
and a friction drive with an automatic pressure control. 

Difficulties of Transmission. The Homer Laughlin car, a bottom 
view of which is shown in Fig. 346, makes use of an original type of 








GASOLINE AUTOMOBILES 


481 


universal joint to transmit uniform angular velocity. Its design was 
brought about by the fact that the rate of transmission of angular 
velocity through a universal joint is not even when the shafts are at 
an angle. This is the fundamental difficulty every designer of a front 
drive has to overcome or suffer the twisting of the axle. 

The front wheels and the flywheel must rotate at practically a 
uniform speed, at least through each revolution. The irregular rate 
of transmission through the universal joint must be taken up some¬ 



where. The normal action of a universal joint at certain angles is 
to make four jerks in a revolution, as it has four fast points and four 
slow points. The Laughlin joint gives uniformity of rotation with 
75 per cent on each side of normal, the difference being taken up by 
the flexibility of the transmission parts. 

Friction-Disc Transmission. The transmission is of the friction- 
disc type, but the disadvantage of this form of drive—the fact that 
the control is reversed—is eliminated. r lhe usual clutch control is 
provided, but the pressure is automatic. This pressure is obtained 
by an eccentric connection by means of which dcsigneis obtain irre- 





















































482 


GASOLINE AUTOMOBILES 


versible application of spring pressure. The transmission locks at the 
correct pressure through the friction of the eccentric. The spring 
controlling the friction for driving provides the proper pressure for 
running, but it is not sufficient for starting or climbing long hills in 
the low gear. The pedal shaft operates a dog that presses down on 
the eccentric sheave extension. To de-clutch, the operator presses 
the pedal down, releasing the clutch. The pedal has two points at 
which it latches, providing extra pressure, and an extra spring is 
brought into service for the high and low speed. This spring operates 
through a toggle linkage. As the pedal rises, the applied power 
increases. When the car attains momentum, the driver depresses 
the pedal until it latches. The running pressure is sufficient to hold 
the engine in all gears except the low and reverse. 

Control. Complete control is obtained through one gearshaft, 
the lever working forward for progressive, and back for reverse. Auto¬ 
matic latching is obtained in every gear, the latch working in sockets 
sunk in the jackshaft. Chain drive is employed between the trans¬ 
mission and front axle. The brakes are located on the rear axle. 
Fig. 347 shows the method of obtaining a conventional pedal control 
of the transmission through the irreversible application of spring 
pressure—one spring for ordinary service, the other for low gear work— 
controlled by the eccentric on the jackshaft of the driving mechanism. 

Four=Wheel Driving, Steering, and Braking. The four-wheel 
drive—a construction in which all four wheels of the vehicle drive, 
and frequently steer and brake—is confined to commercial vehicles. 
A brief consideration of the actions which may have to take place at 
the same time in such an axle will give a very good idea of the problem 
which must be worked out. The wheels must be free to turn about 
the axle as an axis, being driven from their hollow centers; the wheels 
must also be free to turn about the pivot point as an axis swinging in 
a horizontal direction and must be driven steadily all the time. 
All the turning, swinging, and driving action must be outside of 
and beyond the spring supports of the chassis, since the body cannot 
turn; but the axles must at the same time support the springs. 
Further, if all four wheels are to carry brakes, they must be appli¬ 
cable at any and all times and at any and all angles of inclination of 
the wheels, either in a vertical or horizontal direction, and they must 
be so equalized as to apply equally to all wheels, no matter how the 



GASOLINE AUTOMOBILES 


483 


force is applied to the system, and no matter in what position the 
wheels may be. 

The advantage of the four-wheel drive and with it the four- 
wheel steer and brake is granted by eminent engineers, as is also its 



Fig. 348. Side View of a Four-Wheel Drive, Steer, and Brake Motor Truck 


necessity for heavy commercial trucks, but its use has not been 
extensive for the simple reason that it is a complicated arrangement 
at best. In many cases, the design has been so complicated and 
unmechanical as to cause failure, and the reports of these troubles have 
given the four-wheel driving, steering, and braking device a sort of 
visionary air, so that any one talking of it is supposed to be a dreamer. 
Such is not necessarily the case, for many different practical four- 
wheel combination driving, steering, and braking devices have been 
brought out, built, tested, and proved efficient. 

A number of four-wheel designs for commercial cars are being 
marketed, and have proved the contention of their makers that they 
are economical in operation and maintenance. 

Four=Wheel Steering Arrangement. With the design shown at 
Fig. 348, steering knuckles are eliminated, the wheels being con- 



Fig. 349. Details of Axle of the Four-Wheel Drive Truck Shown in Fig. 348. 


nected to the axle ends through the medium of vertical trunnions. 
These trunnions bear on the wheel ball-bearing ring, which is ample 
in diameter and turns freely because of its size and the use of ball 








































484 


GASOLINE AUTOMOBILES 


bearings. Within this ring, the axle terminates in what is practically 
a universal joint, driving through to the outside of the wheels. The 
wheels are thus free to run about a point in the axle ends, at the same 
time taking their power through the inside rotating shaft. Fig. 349 
illustrates one of these axles with the parts lettered. Here II is the 
point of attachment of the driving propeller shaft, G the cast-steel 
one-piece case, F the differential gear within the large driven bevel 
gear 0, MM the vertical trunnions upon which the wheels rotate, and 
NN the universal joints which drive the wheels. 

How the steering is obtained is shown in Fig. 350. At the front 
of the chassis is the steering wheel P; turning it partially rotates the 
longitudinal shaft Q, which extends the length of the chassis. This 
shaft carries levers RR near its two ends, which are connected to 



Fig. 350. Diagram Showing Steering Action of a Four-Wheel Drive Truck 


the steering rods S S. These rods connect to the steering levers U U , 
which are fixed to the wheels themselves instead of to the steering 
knuckles as in the ordinary case, for this car has no steering knuckles. 
In addition to the steering rods attached to the longer of the two steer¬ 
ing levers, there is a cross-connecting rod T T at each end, which con¬ 
nects the two steering levers. Thus, when the levers R R move the 
rods S S, and through these the levers U U, which in turn move 
the wheels V V, the rods TT also come into play and move the 
levers WW and the wheels A" A". Therefore, the movement of the 
steering wheel in any given direction, as to the right, turns all four 
wheels, the front two to the right, and the rear two to the left so 
that they form arcs of the circle in which the front ones are turning. 
The truck thus makes the desired turn to the right in one-half the 



























GASOLINE AUTOMOBILES 485 


distance or time of the ordinary 
truck. Four-wheel steering then 
has the advantage over two- 
wheel, or ordinary, steering, of 
requiring only one-half the space 
and one-half the time to accom¬ 
plish a given turn. The vehicle 
described would turn completely 
around in a circle of 40 feet, the 
outermost circle shown in Fig. 
350 being 56 feet in diameter. 

Chain Four-Wheel Drive. 
Fig. 351 clearly illustrates a bot¬ 
tom view of the Hoadley four- 
wheel drive, four-wheel steer, and 
four-wheel brake truck. The 
power of the engine is trans¬ 
mitted through shafts, gears, and 
universal joints to the differen¬ 
tials; there is a third differential 
in the gear box at the center of 
the frame. Final drive is by 
chain; both ends of the truck are 
exactly alike in so far as the four- 
wheel drive is concerned, and the 
fifth wheels run in ball bearings. 
Steering is accomplished by means 
of worm gearing, the shaft being 
clearly shown, and both sets of 
wheels are steered simultaneously. 

Jeffery Quad. An example 
of the successful development of 
the four-wheel drive is the Jeffery 
Quad, Fig. 352, which has given 
an excellent account of itself in 
government work. In this type 
it will be noted that the inclined 
driving shafts, shown in Fig. 348, 




Fig. 351. Four-Wheel Drive, Steer, and Brake System 





























































486 


GASOLINE AUTOMOBILES 


have been carried lip to the gear box with a universal joint on either 
side. This construction has resulted in a much more inclined shaft 
in each case, but it has also eliminated the tail shaft D, the use of a 
silent chain E with its housing, the central universal joint, and the 
spherical bearing K, and, in addition, it has simplified both shafts. 

In the four-wheel drive vehicle the engine was placed on the 
center line of the car; on the Jeffery it is set off to one side, while the 
two driving shafts to the front and rear axle, which form a continua¬ 
tion of each other, are set off to the other side. This result is produced 
by making the transmission very wide with three side-by-side shafts, 
as shown in Fig. 353. The engine drives the splined shaft II , on which 
are gears that transmit the rotation to the intermediate shaft C, which 
through the final gears E and F, drives the final shaft, which is in two 



Fig. 352. Plan View of the Jeffery Quad, Showing Disposition of Units 
Courtesy of Thos. B. Jeffery Company, Kenosha, Wisconsin 


parts, B driving one pair of wheels, G driving the other pair. Note 
that the differential has been incorporated in this type of drive, 
so that it is possible to have a different drive for the front wheels 
from that for the rear wheels. 

The rest of the construction is too simple to require a detailed 
description beyond the simple statement that the gear box gives four 
forward speeds and one reverse. When the two ordinary shifters 
are in the neutral position shown, reverse is produced by shifting 
the double reverse gear on shaft D along until its left-hand member 
meshes with the second-speed gear on shaft A and its right-hand 
member with the low-speed gear on shaft C. 

Universal joints fit on the two tapers B and C with shafts 
inclined to the two axles. On top of the stationary axle of the I-beam 


















GASOLINE AUTOMOBILES 


487 


section is fixed a small box which contains the bevel gears and an 
additional differential with suitable bearings, the whole being 
enclosed. These can be seen in Fig. 352, that on the rear axle being 



Fig. 353. Plan View of the Transmission of the Jeffery Quad, Showing the Shafts for Both Axles 


plainly shown, while the one in front is partly obscured. This 
member is shown in detail in Fig. 354, which gives the longitudinal 
section along the driving shaft at the left, in which the axle II is 
noted, the bevel gear I, and the bearings for radial and thrust loads 



Fig. 354. Sections Showing Bevel Drives at the Axles on Jeffery Quad 


at J and K, respectively. The driven shaft is seen at L, with the 
sleeve M around it, the sleeve being used to drive to the differential 
case, since the larger, or driven, bevel C is not sufficiently large to 
house the differential P. 























































































































































































































488 


GASOLINE AUTOMOBILES 


Fig. 355 is a diagram showing the details of the axle end and 
wheel construction. In this, H is the I-beam section of the axle bed 
shown in Fig. 352, and N one of the shafts, which carries at its 
end the universal joint Q, with the end of the shaft extending beyond 
the joint R. The latter carries the spur gear S, which meshes with 



the internal gear T fixed to the wheel and drives the vehicle in this 
manner. It will be remembered that this is not necessarily a front 
wheel, but any one of the four. 

The wheel turns on the spindle U, which is part of the steering 
knuckle V; this knuckle turns upon the pivot W. The lever which 













































































































































GASOLINE AUTOMOBILES 


489 


turns the wheel is attached at A r , the pair (either both front or both 
rear wheels) being connected by means of a cross-rod; at one end of 
this rod there is a connection to a rod which runs the entire length 
of the chassis. This rod is operated by means of the steering gear, 
and imparts the same motion to the front wheels as to the rear, 
except that the two are in opposite directions, that is, front wheels 
turn to the left and rear wheels to the right, so that they will follow 
around in a correct circle. 

Advantages of Four-Wheel Drive. It is claimed for the four-wheel 
drive that its four-wheel steering reduces the mileage traveled to the 
minimum in that the car can run closely to corners and travels less in 
crowded traffic, in turning around, and in approaching and leaving 
loading platforms. The push of the rear wheels and pull of the front 
wheels enables it to surmount obstacles instead of bumping over 
them, and its greater traction permits it to travel soft roads not 
easily negotiated by the rear-drive type of trucks and cars. The 
four-wheel drive type will turn in a 48-foot circle, and, with its lock¬ 
ing differential, obtains traction on slippery roads. 

Electric Drive. When the final drive is electric, or when the 
source of power is an electric motor, the matter of four-wheel driving 
is much simplified, the wheel carrying the electric motor attached 
directly to it and turning with it about the knuckle pin. Both 
wheel and motor are turned by means of a worm and gear above, the 
wheel being attached to the upper end of the steering-knuckle pin 
prolonged. Turning this turns the wheel and motor. 

This steering wheel is turned by the worm, which is on one end 
of a cross-shaft. This shaft is carried in bearings above the stationary 
bed of the axle and has near the center a bevel gear that meshes 
with another bevel, which is, in turn, attached to the lower end of the 
steering post. Turning the steering wheel turns the post and the 
bevel gear, which turns the bevel pinion and with it the worm shaft. 
The shaft turns the worm and the worm wheel which actuates the 
road wheels. The driver thus has a triple reduction between himself 
and the wheels, giving him this much advantage in steering: there is 
the leverage of the wheel of large diameter, the ratio of the sizes of 
the two bevels, and the ratio of reduction of the worm gearing, which, 
in addition, is irreversible. The steering gear is thus eliminated and 
four simple gears substituted for it. 


490 


GASOLINE AUTOMOBILES 


Couple-Gear Type. In the Couple-Gear wheel, which is an 
American product, the motor is placed inside of the wheel a type 
especially designed and constructed for this purpose. With the 
motor in this position, the wires enter through the hollow hub, 
altering its construction very materially. As compared with the 
electric motor on each wheel, previously described, this form has the 
advantage of greater simplicity, fewer parts, superior appearance, 
and protection against the elements, while the enclosed position of the 
motor, which is the most delicate part of the machine, protects it 
against road obstructions and accidents. This arrangement also 

simplifies the steering 
problem, since the car is 
steered just the same as 
any other truck, much 
of the complication inci¬ 
dent to an electric motor 
on each wheel being elim¬ 
inated . 

Fig. 356 is a view of 
the wheel with the tire 
removed and the whole 
disconnected from the 
axle ends. Aside from 
this, it is complete and 
ready for use. Note how 
the axis of the motor is 
set at a very slight angle, 
just sufficient to allow a 
pair of very small driving gears at the two ends of the armature shaft 
to drive on opposite sides of the wheel. The wheel is assembled with a 
pair of driven gears on either side, these being separated a compara¬ 
tively small distance, about 2\ to 3 inches. As stated, the armature 
shaft has a small bevel pinion on each end, each of these meshing with 
the driven gears, but on opposite sides. It is this arrangement which 
gives the device its name of Couple-Gear. In this figure the brake 
band has been removed, but the brake drum will be seen just ifiside 
the wheel at A. Beyond this is noted the spindle B, which is made 
hollow for the wires from the battery and turns in a bearing on the axle. 



Fig. 356. End View of Couple-Gear Electrically Driven 
Wheel with Tire Removed . 




GASOLINE AUTOMOBILES 


491 


In the second illustration, Fig. 357, an axle, either front or rear, 
with the wheels removed, is presented. In this cut the left wheel is 
entirely removed, but the one on the right shows the axle spindle B, 
the method of fixing it in the axle support at C; the armature housing 
D is normally within the wheel and not visible. One feature peculiar 
to this arrangement is the steering, which is effected by means of 
a vertical post with a small spur gear at its lower end E. This 
meshes with a curved rack F, which is machined on the outside of 
a pivoted member G, to which a pair of arms are attached. One of 
these arms Ii has a rod I, which runs to and operates the right-hand 
spindle B, while the other J has a similar rod K, which operates the 
left-hand wheel. When all four wheels are to be driven in this 
manner, the post is vertical, but the connection with the rack F 



j 


Fig. 357. The Couple-Gear Axle and Parts, Showing Method of Operation 
Courtesy of Couple Gear Freight Wheel Company, Grand Rapids, Michigan 

becomes horizontal, with a continuation to the rear axle which 
operates the various arms, levers, and rods there in the same manner. 

This particular system is used for heavy commercial work only, 
and in this it has been particularly successful as a tractor, a front axle 
and a pair of wheels being substituted for those of a heavy trucking 
wagon. Then, with a sling under the body or beneath the driver’s seat 
for the batteries, and with proper wiring, control levers, and steering 
wheel, the truck becomes electrically driven. 

FRONT AXLES 

TYPES 

Classification. Generally speaking, front axles may be divided 
into about five classes: the Elliott, the so-called reversed Elliott, the 
Lemoine, the front-drive form, and the fifth-wheel form. 











492 


GASOLINE AUTOMOBILES 


These typical forms of axles are themselves subject to further 
subdivisions. For example, there are many different forms of Elliott 
axles, each manufacturer having what is practically his own form. 
Again, the Lemoine, when used by other firms, has been built in a 
practically new form, taking the second maker’s name. Thus the 
form of front axle made by Lemoine for Panhard is so different as to 
be called the Panhard, and not the Lemoine. The same is true of 
the Lisses axle made by Lemoine. In this country, it is claimed 
that the axles made by Timken are sufficiently different from the 
Elliott and reversed Elliott, from which the principle was taken, as to 
deserve the name of Timken axles. It should be borne in mind that 
in the following description of the various axle types the forms of 
material, and the shape, size, and kinds of bearings used do not alter 



the principle upon which the axle is constructed, although they do 
alter the appearance. 

Elliott Type. In general, a front axle consists of a bed, or axle 
center; a pivot pin or knuckle pin upon which the knuckles may turn; 
and the knuckles themselves with the attachment for turning them. 
The Elliott type, Fig. 358, the form in which the end of the axle 
takes a U-shape, is set horizontal and goes over the knuckles. 
The knuckles have plain vertical ends bored for the pivot pin, which 
passes through and has its bearing in the upper and lower halves of 
the axle jaw. In this form, the thrust comes at the top, where the 
axle representing the load rests upon the top of the knuckles that 
represent the point of support. 

Reversed Elliott Type. In the reversed Elliott front axle, as the 
name would indicate, the action is just reversed in that the axle end 



















































GASOLINE AUTOMOBILES 


493 


forms a straight vertical cylindrical portion bored for the pivot pin, 
while the knuckles are so formed as to have jaw ends which go over 
the axle ends. The thrust comes at the bottom of the knuckle, 
where the axle bed rests upon the upper face of the lower jaw of the 
knuckle, the axle representing the load and the knuckle the support, 
just the reverse of the previous case. 

This will, perhaps, be made clearer by illustrations. In Fig. 
358, as already mentioned, the axle has the jaw ends, and the thrust 
comes at the top. This is indicated in the figure by the letter A, 
which calls attention to the thrust washers at the top. Fig. 359 
shows an axle of the reversed Elliott type, this being the front axle 



Fie. 359. Reversed Elliot Type of Front Axle and Steering Knuckle 

t 


for a heavy truck. In this the thrust washers A are at the bottom, 
and are of hardened steel, ground top and bottom to a true surface; 
the upper surface is doweled to the axle, while the lower is doweled 
to the knuckle. This form has the real advantage of concentrating 
all of the difficult machine work and assembling it into one piece, 
the knuckle. The Elliott type, on the contrary, makes the knuckle 
and axle difficult pieces to handle in the machine and afterward, this 
being shown in the cost. Ease of machining the bed of the axle 
is a great advantage, for the axle will average about 44 inches in 
length for a standard tread of 56| inches, and longer for wider treads, 
up to a maximum of about 48 inches for the wide-tread standard in 

the South. 

























































































494 


GASOLINE AUTOMOBILES 


The ordinary automobile machine shop is not fitted up for work 
of this size, particularly in machine tools other than lathes, and this 
job could not be done on a lathe. The result is that it becomes a task 
to handle it, necessitating special and expensive rigging for that one 
job. This was the case with the axle shown, a boring mill of the hori¬ 
zontal type and a large size milling machine being used on it. Both 
of these had to have special fixtures, which were useless at other times, 
to hold and machine these parts. At that, this job was much easier 
than an axle of corresponding size in the Elliott type would have been. 

Lemoine Type. The Lemoine type of front axle differs from 
those described in that the axle proper bears upon the top or bottom 
of the knuckle-pin part of the knuckle, the two being made as one; 
that is, an extension or a jaw of the axle does not support the knuckle 

as with the Elliott type. 
When the steering knuckle 
of the Lemoine type is 
mounted below the axle 
stub, the latter is carried 
higher than with the re¬ 
versed Elliott, so as to 
rest upon the top of the 
knuckle. An advantage of 
the construction from a 
manufacturing viewpoint 
is the cost of machining. 
With this design, the thrust load is practically entirely at the bottom 
upon the knuckle, which also must take all side loads; it is fastened 
in a sidewise direction at but one point—the bearing in the axle. The 
side shocks are taken on the end of a beam fixed only at the other 
end, whereas with the other types, the load is distributed between 
two supports, or divided equally over two sides, the point of support 
being midway between them. With the Lemoine type discussed, 
the bottom bearing must compensate for radial and thrust loads— 
a difficult condition to meet. 

While the design is easy to machine, assemble, and handle, its dis¬ 
advantage is that the knuckle has a double duty, having, as it does, both 
radial and thrust loads to care for because of its one-piece construc¬ 
tion. This type of axle is, however, very popular with foreign designers. 



Fig. 360. Inverted Lemoine Type of Axle 
as Used on Overland Cars 



















GASOLINE AUTOMOBILES 


496 


I 


Inverted Lemoine. A novel type of axle has been created in the 
1916 Overland car, Model 75, called an inverted Lemoine. In 
this type, as Fig. 360 shows, the wheel spindle, or stub axle, is at 
the top of the steering knuckle instead of at the bottom as in the 
case of the regular Lemoine type. The knuckle has a single, fairly 
long support in the end of the I-beam front axle, the forging being 
much simpler on this account. In fact, this makes the axle nearly 
straight, which doubtless accounts in large part for this unusual 
design. One real advantage of this design is that it allows the car 
weight to be low in relation to wheel bearings, thus assisting in steering. 


Fig. 361. Novel Front Axle Design Used on the New Light-Weight Marmon 
Courtesy of Nordyke and Marmon Company, Indianapolis, Indiana 

Marmon Self=Lubricating Axle. The new Marmon front axle, 
Fig. 361, is of the inverted Lemoine type similar to the Overland, 
shown in Fig. 360, but at first glance it looks quite different. For 
one thing, the bearing in the axle end is different, and in this 
lies an exclusive and valuable feature. The stub-axle pivot pin, 
made integral with the stub axle, is placed in a split bushing, which 
is a tight fit at the bottom—where the thrust collars are formed in it— 
and at the top, but not in the middle. When this bushing is in place, 
the knuckle and bushing are forced into the axle end from above, 
and a kind of hub cap screwed on at the bottom. This holds it 
permanently in place. 












































496 


GASOLINE AUTOMOBILES 


Near the middle of the split bushing there is a narrow slot to 
which a central bolt hole is connected. On being assembled, the 
inside is filled with lubricant, which cannot escape; but, as it wears 
away, the central bolt can be removed, more lubricant can be poured 
in until it is full, and the bolt replaced to prevent leakage. In this 
way the axle is self-lubricating, and, as the oil is used up very slowly, it 
needs practically no attention. 



Fig. 362. Front Elevation of Car, Showing Camber of the Front Wheels 


Like the Overland, this arrangement of the axle end brings the 
axle down low, relative to the weight, and consequently steering is 
made easier. The lowering of the axle also brings the points of 
spring support down and thus lowers the whole car. 

Camber Somewhat Complicates Axle Ends. All front wheels 
are dished, that is, the spokes do not lie in a flat plane but in the 
form of a cone, with the point of the cone at the outer end of the 
hub and the base of the cone at the rim of the wheel. Now all roads 







































































GASOLINE AUTOMOBILES 


497 


and most all pavements are made with a camber. The center of the 
road is made higher than the sides so that the road will drain. It 
is necessary, in order to have the lower spokes plumb or perpendicular 
to the road surface, to throw the center line of the wheel out of the 
vertical plane 2 or 3 degrees. This offset is also called camber, and 
it complicates the construction of the axle ends to such an extent 
that they must be machined with this slight angle either in the 
knuckle or in the axle, or distributed over the two places. 

Fig. 362 shows the effect of this camber upon the front appear¬ 
ance of the car, the slight angle of the front wheels giving the car a 
bow-legged appearance. 

Gather Further Complicates Axles. What the carriage men 
term “gather” further complicates the axle ends. This is the practice 
of setting the axle so that the front wheels are closer together at 
the front than at the rear, that is, they toe in. The idea of this is 
to make steering easier and, more particularly, to make the car 
self-steering on plain, level, straight-ahead roads. It is scarcely 
noticeable from in front, but is from above. Although many cars 
still have it, it is not used as much now as formerly. 

MATERIALS 

The materials utilized for front axles include castings of steel, 
manganese bronze, iron, and other metals, in the form of forgings, 
drop forgings, drawn or rolled shapes, and pressed shapes. Wood 
has been but little used and only in the past. 

Cast Axles. Castings for front axles have been looked upon 
with grave doubt and fear by designers and owners, because of 
the fact that road shocks are more severe for front than for rear 
axles, and because of the fear that a casting may have a blowhole 
or some other defect. In addition to the natural distrust of castings 
for this work, it was feared that such material would crystallize more 
quickly than would a better and more homogeneous material like 
steel. There is, of course, a certain amount of crystallization in all 
materials, but far less in a close-grained fine-fibered structure like 
forged or rolled steel than in any form of casting. Aside from this, 
castings present many other advantages which are well worth while. 
Thus, the spring pads may be cast integral with the axle with prac¬ 
tically no extra charge, while the same forged integral with a drop- 


498 


GASOLINE AUTOMOBILES 


forged axle may easily add several hundred dollars to the cost of the 
dies. Again, with casting patterns, the fillets may be changed easily 
to give a greater section here or to reduce a section there, while a 
similar action with any forged axle means a new set of dies, costing 
perhaps 8600. There are many other machining helps which may 
be provided in cast axles without any extra cost. 

Notwithstanding these many advantages, the casting for the 
front axle has been and is distrusted, and the makers who have used 
it have flown in the face of popular prejudice, for the public has 
mistrusted it even more than the makers. For this reason, the cast¬ 
ing has been little used, and the writer fails to recall a single car 
with a cast axle now on the market. 

Forgings. Forgings, as distinguished from drop forgings, are 
much used for good front axles, but are expensive. The writer knows 
of one excellent truck builder, striving to build the best truck in the 
world, who is using a hand-forged front axle, the end of which is 
shown in Fig. 359. It is forged down from a 6-inch bar of selected 
steel and the ends worked out so as to leave the bed proper a 2\- by 
2§-inch section, which later has been increased to 3 inches square. 
This made a very costly piece of work, but the stand-up qualities 
shown in actual work more than made up for it as long as people could 
be found to pay the price demanded for a truck made along these lines. 

Many smaller makers follow out the same scheme, the lighter 
work allowing the axles to be forged up much more quickly, more 
easily, and more cheaply. The smaller the amount of material to 
be heated, the less difficult will be the work, and the more quickly 
will progress be made. The general trend of axle practice today, 
however, is to turn over the axle job to specialists in that line, most 
of whom employ drop forgings, drawn- or rolled-steel tubing with 
drop-forged ends, or similar rapid-production forms of construction. 

Drop Forgings. Drop forgings are now more used than any other 
form, although the first cost is great, for the dies must be very care¬ 
fully worked out in a very high grade of steel; the result is a large 
expense of possibly $600 to $750 before a single axle is turned out. 

As a matter of fact, with drop forgings, after the die is once 
made, the axles may be turned out rapidly, accurately, and with 
little labor and cost. Given the dies, therefore, there is no doubt 
that this method produces an axle at a very low first cost. Moreover, 


GASOLINE AUTOMOBILES 


499 


the method itself produces better quality, for any process which 
works steel or wrought iron over and over again improves its quality, 
provided the steel is not burned in the process of heating. Not only 
are the majority of axles made of drop forgings, but of those not so 
made some part is almost sure to be a drop forging, as, for example, 
those made of steel tubing which have their ends or other parts 
made by the drop-forging process. In Fig. 363 is shown a drop- 
forged axle used on a truck. 

Tubular Axles. The I-beam section of front axle is universally 
used, and while the tubular type formerly enjoyed some popularity, 
its use today is confined to a very few vehicles. When employed, 
its ends are drop forged or drawn, or rolled steel may be used 
with the ends welded or otherwise secured. The disadvantage of 
the tubular type is the fastening of the ends which is more or less 
offset by the lowered cost of material. 



Drop-Forged Ends. Nearly all the ends for axles made in this 
way are drop forgings, very few castings being used, while the spring 
pads, or spring seats, as they are sometimes called, are split into 
upper and lower halves and bolted on. 

The loading conditions of all front axles are such that the load 
rests on the axle at two points inside of the supporting points— 
the wheels. Thus, the continual tendency of the load acting down¬ 
ward and of road shocks acting upward is to bend the center of 
the axle still further downward. Since a tube which has been bent 
once has been weakened, it follows that this tendency to weaken it 
presents a further source of trouble. 

Pressed=SteeI Axles. The pressed-steel type of axle, which 
made its initial appearance in 1909, and is not generally employed, 
consisted of a pair of pressed-steel channel shapes—one being 


i 


























































500 


GASOLINE AUTOMOBILES 


slightly larger than the other—set together with the flanges 
inward so as to present a box-like shape. When thus arranged, the 
two sections were riveted together by a series of rivets running ver¬ 
tically along the center part of the channels. The ends consist of 
drop forgings, machined to size or space between the channels when 
assembled, and then set into place between the ends and riveted. 
The pressed-steel construction obtained a secure attachment to the 
bed. This axle was of the Elliott reversed type. 

Change of Axle Type Simplifies. Often the change from one 
type of axle to the other is not made because the latter is better but 
because of some incidental saving in the manufacture. Thus, in 



Fig. 364. Differences in Construction of Reversed Elliott and Elliott Types of Axle Knuckle 


Fig. 364, we see the reversed Elliott type at the left at A and the 
Elliott type at the right at B. From a manufacturing point of view, 
the former is much cheaper to construct, for the axle and knuckle 
costs would just balance one another, but the forging and machining 
of the one-piece steering arm shown in B would be more than double 
that shown in A. Moreover, the number of dies and their cost 
would be about three times as much, while the customer would have 
to be charged two or three times as much for repair parts. That is, 
in a modern low-priced car, produced in tremendous quantities, the 
advantages and costs connected with the two-piece steering arm of 
A would influence the choice of that design, regardless of other 
advantages or disadvantages. 































GASOLINE AUTOMOBILES 


501 


AXLE BEARINGS 

Classification. Thus far nothing specific has been said about 
axle bearings. These are, according to construction, of three kinds: 
plain, roller, and ball. From the standpoint of the duty which 
they are to perform, bearings may be divided into radial-load and 
thrust bearings, all three forms mentioned above being used for 
both purposes, but arranged differently on account of the difference 
in the work. Each one of the three classes may be further subdivided. 
Thus, plain bearings may be of bearing metal or of hardened steel, 
or they may even be so constructed as to be self-lubricating. Again, 
plain bearings may mean no bearings at all as in the old carriage 
days when the axle passed through a hole in the hubs, and whatever 
wear occurred was distributed over the inside of the hubs, resulting 



Fig. 365. Front Axle End, Showing Roller Bearings for Wheel 
and Steering Knuckle 

after a time in the necessity for either a new set of hubs or a new axle, 
or for the resetting of the axle, so that the hubs set further up on a 
taper. Roller bearings may be of several classes, some makers using 
both straight and tapered rollers. In addition to these there are 
combinations of the straight and tapered types, and bearings with 
two sets of tapered rollers acting back to back, the action being that 
of straight rollers, with the end-adjustment feature of the tapered 
type. There are also many types of ball bearings, as, for example, 
plain ball bearings—those working in flat races, those working in 
curved races, those working in V-grooved races, and single balls 
working alone. There are also combinations of balls in double rows. 










502 


GASOLINE AUTOMOBILES 


Roller Bearings. Fig. 359 shows the use of tapered roller bear¬ 
ings for the hubs and of hardened-steel thrust washers for the thrust 
load, the figure showing, in addition, a plain brass bushing in the 
axle for the knuckle pin to turn in. In Fig. 365 is shown a more 
elaborate use of roller bearings of very excellent design. In addition 
to the axle bearing, it will be noted that the top bearing of the steer¬ 
ing knuckle is of the roller type. 

Ball Bearings. Although there is a growing tendency to utilize a 
short adjustable type of roller bearing, many designers favor the ball 
bearing. The two most common forms are the cup and cone type, 
which cares for radial and thrust loads, and the annular form which 



Fig. 366. Front Axle and Steering Knuckle of Superior Construction 


is suited for supporting annular loads. The annular form is not 
adjustable, and when it wears it must be replaced with a new bearing. 
The cup and cone type is adopted by makers of low-priced and 
medium-priced cars, has an angular contact, and is adjustable. 

In some instances, particularly with high-grade cars, ball bearings 
are used for the knuckle bearings as well as for the hub. Fig. 366 is 
an example of an axle end, which for real bearing worth, has probably 
never been surpassed; this is the axle end and steering knuckle of a 
very high-priced car, not now made, but one on which no expense 
was spared to make it perfect. The illustration shows the wheel 
hubs running on two very large diameter ball bearings, while the 
knuckle also turns on two very large ball bearings arranged for 









GASOLINE AUTOMOBILES 


503 


radial loads. At the top is another ball bearing arranged for 
thrust; this bearing taking up all thrust loads from the weight above 
or from road inequalities. Fig. 367 illustrates the cup and cone type, 
This design utilizes ball bearings for the hubs and plain steel thrust 
washers on the knuckle. 

FRONT AXLE TROUBLES AND REPAIRS 

Alignment of Front Wheels Troublesome. The lack of align¬ 
ment of front wheels gives as much trouble as anything else in the 



Fig. 367. Front Axle Details of Waverley Electric Car 
Courtesy of the Waverley Company , Indianapolis, Indiana 


front unit. This lack not only makes steering difficult, inaccurate 
and uncertain, but it also influences tire wear to a tremendous extent. 
As Fig. 368 indicates, even if the rear axle should be true with the 
frame, at right angles to the driving shaft, and correctly placed 
crosswise—correct in every particular with the shafts both straight 
so that the wheels must run true—the fronts may be out with 
respect to the frame, out of track with the rears, or out with 
respect to each other. 

In order to know about the front wheels, they should be meas¬ 
ured; while this sounds simple, it is anything but that. In the first 



















































































































504 


GASOLINE AUTOMOBILES 


place there is little to measure from or with. A good starting place 
is the tires, and a simple measuring instrument is the one shown in 
Fig. 369. This instrument consists of a rod about | inch in diameter 
and about 3 feet long, fitted into a piece of pipe about 2 feet long, 
with a square outer end on each, and a set screw to hold the meas¬ 
urements as obtained. By placing this rod between the opposite 
sides of the front tires, it can be ascertained whether these are par¬ 



allel, and whether they converge or diverge toward the front. But 
knowing this, the driver or repair man is little better off than before, 
because this may or may not be the practice of the makers of the car, 
and it may or may not cause the trouble. 

In short, a more accurate and more thorough measuring instru¬ 
ment is needed, Fig. 370. Such an instrument can be bought, but a 
similar outfit can be made from f-inch bar stock, using thumb nuts 


a 


Rod 


3 


-Set Screw 


Pipe-? 


Fig. 369. Simple Measuring Rod for Truing-Up Wheels 


where the two uprights join the base part, and also at the two points, 
or scribers, on these uprights. Having the floor to work from, the 
heights can be measured, and thus the distance between tires may be 
taken on equal levels. Thus, a bent steering knuckle can be detected 
with this apparatus. Similarly, the center line and frame lines of 
the car can be projected to the floor, and by means of the instrument, 
it can be determined whether the axle is at a perfect right angle 








































GASOLINE AUTOMOBILES 


505 


with the frame lines, and whether the wheels are perfectly parallel. 
Given the frame line, too, it can be determined whether the wheels 
track with one another. 


Straightening an Axle. When an axle is bent, as in a collision, 
a template is useful in straightening it. This can be cut from a 
thin sheet of metal, light board, or heavy cardboard. It is an approx- 



Fig. 370. Accurate Measuring Rod for Truing-Up Wheels. Better Design than Fig. 369 


imation at best and should be used with great care. Fig. 371 shows 
such a template applied to an axle which needs straightening. 

When the axle is bent back to its original position, a pair of 
straightedges laid on top of the spring pads will be of great assistance 
in getting the springs parallel, as the worker can look across the 
straightedges with considerable accuracy. This is indicated in the 



first part of Fig. 372, which shows the general scheme. It shows also 
how the axle ends are aligned, using a large square on top of a 
parallel bar, but of course this cannot be done until the last thing, 
at least not until the spring pads are made parallel. 

Front axles of light cars may be straightened without removal, 
provided the bend is not in the nature of a twist and not too short. 
Take two hardwood planks 7 feet long, 10 inches wide, and 2 inches 






























50G 


GASOLINE AUTOMOBILES 


thick. Next, cut four f-inch blocks 10 inches long and 3 inches wide. 
Lay the blocks flat between the planks, space them about 2 feet apart, 
and bolt the whole securely. This obtains a girder 7 feet long, 10 
inches wide, and 4f inches thick. Next, take two pieces of 4X4 timber 
3 feet long and cut a tenon on one end of each. Make three f-inch 
eye bolts, 12 inches long, with nuts and plate washers for each. Place 
one of the eye bolts between each pair of blocks and screw up the nuts 
and washers sufficiently so as to rivet them. This permits of moving 
the eye bolts to any position between the blocks. Two small steamboat 
ratchets and several short but strong chains complete the equipment. 



With an axle bent back in the center, lay the girder on blocks in 
front of the car so it will be level with the axle, place the tenons of 
the 4X4 timbers in the space between the planks of the girder, one on 
either side of the bend, and connect the axle to the girder by means of a 
chain, the ratchet, and the eye bolt. When the ratchet is tightened up, 
it draws the ends of the4X4’s against the axle on either side of the bend. 
Tightening the ratchet still further removes the bend. This work 
may be accomplished in 20 minutes or less or in about one-tenth the 
time it will require to displace the axle, heat it, and straighten on an 
anvil, etc. The apparatus can be used for straightening many differ¬ 
ent bends; all that is necessary is a different arrangement of its parts. 



























GASOLINE AUTOMOBILES 


507 


For example, a downward bend can be straightened by placing the car 
above the girder, connecting the axle to the girder, and using a short 
screw jack to remove the bend. This device can be used with success 
in shops dealing with light- or medium-weight cars. 

Spindle Troubles and Repairs. Wear of the spindle, or knuckle 
bolt, and its bushings, as well as play in the steering-gear linkage, brings 
about wobbling of the front wheels when the car is in motion. Some 
experienced persons mistake wear of the knuckle and the bushings for 
play in the wheel bearings, and attempt to remedy the trouble by 
adjusting the bearings. It is a simple matter to determine the com¬ 
ponent at fault. To test for bearing play, drive a block of wood 
between the knuckle and the axle, then grasp the wheel at the top and 



bottom, or at points diametrically opposite, and test for looseness. 
If none exists, the play is in the knuckle pin and its bushings. The 
remedy is to fit new bushings and new knuckle pins. 

Wobbling Wheels. Wobbling of the front road wheels is gener¬ 
ally due to play in the joints of the steering mechanism, and it is not 
only troublesome, but also sets up undesirable stresses on the steering- 
gear linkage. This flapping of the wheels may be present with the 
steering gear and linkage in perfect operating condition, and similarly 
when the springs, hangers, etc., are in good condition and the proper 
toe in, or gather, of the wheels exist. 

When the wheels wobble it may be assumed that the front springs 
have so settled that the steering pivots are not quite vertical fore and 






508 


GASOLINE AUTOMOBILES 


aft, particularly with reference to that type of pivots which do not 
incline outwards and where the wheels are canted or dished to bring 
their points of ground contact in line with the pivots. A cure for this 
trouble is to place wedges between the front springs and spring seats 
so as to alter the angle of the steering pivots, as shown in Fig. 373. 
Metal wedges are used, about | inch thick at the large end, and 
tapered to a knife-like edge. The wedge is placed at the forward end of 
the axle, and a little experimentation will give the results desired. 
In wedging, as few wedges should be used as is necessary to obtain the 
desired result. 

CHASSIS GROUP 

In arranging a logical presentation of the numerous components 
of the motor vehicle, the chassis is separated from the body. It 
includes the power plant and mechanism utilized in transmitting the 
energy of the engine to the road wheels, also the frame and suspen¬ 
sion, the axles, etc. However, only frames, springs, and shock 
absorbers will be discussed in this section, as the other parts of the 
chassis have been treated. 

Characteristics of Parts. Frames. The chassis frame practi¬ 
cally is the foundation of a motor vehicle, since all of the power 
transmitting and other units are attached to it. Motor-vehicle 
construction depends, to a certain extent, upon the general design 
of the chassis, the construction of the power plant and transmit¬ 
ting units, their mounting, the method of final drive, the wheelbase, 
etc. The size of the material used depends upon the weight of the 
units carried and the capacity of the vehicle, and varies from thin 
and small sizes on very light pleasure cars to heavy structural I-beam 
frames on commercial vehicles. 

The use of pressed steel is becoming more popular, as is also the 
tendency to narrow the frame at the front to obtain a shorter turning 
radius. The majority of designers favor what is termed a kick-up at 
the rear, which affords better spring action and permits of a low sus¬ 
pension of the body. The use of tubing and wood has practically 
been abandoned. There is a slight return to favor of the underslung 
suspension, a form that was popular several years ago but which did 
not then obtain the insults claimed for it, as the springing gave some 
trouble. 


GASOLINE AUTOMOBILES 


509 


Springs. The primary function of the spring is to absorb the 
road shocks that would otherwise be communicated to the mechanism 
and passengers. Considerable progress has been made in the past 
year toward improving springs, and not only are they better pro¬ 
portioned, but improved material and methods of mounting have, to a 
great extent, eliminated breakage. The leaf type, developed by the 
horse-drawn carriage industry, is the form universally employed on 
motor vehicles, both pleasure and commercial. i 

A review of the 1916 springs for cars showed that the three- 
quarter and seven-eighths elliptic spring was favored by 46.5 per cent 
of the makers, while some form of cantilever spring was second with 
28.7 per cent for rear suspension. This year the advocates of the 
cantilever have gained many new recruits. In the matter of front 
springs, the semi-elliptic may be said to practically monopolize the 
field. The coil spring is a thing of the past. 

Shock Absorbers. The fitting of shock absorbers as standard 
equipment is not as noticeable as it was in 1916 and the year previous. 
The use of high-speed engines with light reciprocating parts, and the 
employment of high-grade light material in other components of the 
chassis, together with better springs, serves to absorb shocks created 
by traversing rough roads. A few makers supply shock absorbers, 
but, as a rule, the car manufacturer leaves the selection to the pur¬ 
chaser. Many different types of shock absorbers are marketed, and 
use is made of varying principles. 

FRAMES 

General Characteristics. When the automobile was first intro¬ 
duced, comparatively little attention was paid to the frame, as the 
other components of the chassis, such as the power plant, gearset, 
axles, etc., were held to be of greater importance, consequently the 
frame did not receive the consideration it should. After experiencing 
considerable difficulty, however, due to accidents and other failures 
which were traced directly to poor frame design, the automobile 
engineer found that it was possible to build a frame of great strength 
with less weight than the troublesome types. This statement applies 
to the frame of the commercial car as well. 

The improvement in frame design is the result of the tendency to 
provide perfect alignment of the power plant, clutch, and gearset, 


510 


GASOLINE AUTOMOBILES 


making use of what is known as the unit power plant on some models, 
while on others, particularly of the heavier type, flexible mounting 
of the units has been resorted to. The tendency is toward the use of a 
flexible mounting of all individual units, at least to some degree, in 
order to relieve them of the stresses brought about by frame weaving 
when the road wheels mount an obstacle on the road surface. 

Classes of Frames. The most prominent types of frames, divided 
according to their use, are the pressed-steel frame, the structural 
frame, and the structural I-beam frame; the latter is confined to com¬ 
mercial cars. These classes may be subdivided according to the 
general construction and material, as well as to the distribution of 
the chassis units. 

The material employed is either pressed or rolled steel. The 
wood frame or combinations of wood and metal frames are practically 
a thing of the past, and are to be found, with one or two exceptions, on 
old cars. The steel frame may be constructed in the following shapes: 
channel, L-beam, angle, T, Z, tubing, flat plates, and combinations 
of any two or more of these. ' Other forms are possible. For example, 
the channel may be turned with the open side in or out, the two con¬ 
structions being widely different; or the angle may have the corner 
down and out, down and in, up and out, or up and in. S*milarly, the 
T-shape may be a solid T turned up or down, or it may be a hollow 
T-section with space between what might be called the two sides of 
the leg; this shape may be turned either up or down, while the 
Z-shape may be turned horizontally or vertically. Many frames are 
constructed with the open end of the channel section turned in, and 
use is made of a steel underpan of flat section attached to the under 
side of the main frame. In several instances there is a tendency to 
make the frame and underpan as one piece, in which case the frame 
section assumes the shape of a channel with an exceedingly long lower 
flange. 

Another type of frame is that having a continuous section 
throughout. Others have a varying section. Thus, the ordinary 
steel frame of modified channel section may have a depth of perhaps 
5 inches at the center, a width of upper flange of 1J inches, and a width 
of lower flange of 2 inches. A frame similar to this would taper down 
to the ends to perhaps 20 inches in vertical height, and to 1 inch in 
width of both top and bottom flanges. Then, again, frames which are 


GASOLINE AUTOMOBILES 


511 


bent upward or downward at the ends or in the middle really differ 
from those frames which preserve one level from end to end. The 
practice of bending the chassis frame is very prevalent of late, 
the upturning of the ends bringing about a lower center of gravity, 
making for stability and ease of entrance and exit to the body. 

Tendency in Design. There is a marked tendency toward mak¬ 
ing the chassis frame wider at the rear and narrower at the front. 
In one or two cases the designer appears to have gone to the extreme 
in this respect. The advantage of the narrow front construction is 
that it enables the car to be turned in a shorter radius. The use of a 
wide rear frame provides more space to support a wider body. A 
more recent development is to make the longitudinal bars of the frame 
parallel over the front spring and near the rear spring, and to have 
them tapered from behind the front to the rear springs. A certain 
amount of material is said to be gained by this construction, as no 
heavy reinforcement or sudden offset is necessary to the frame. By 



widening the frame at the rear it makes possible the placing of 
the springs directly underneath the frame. Some car makers have the 
sides of the frame straight over the entire length, but tapered from 
the front to the rear. 

Fig. 374 illustrates what is termed a single drop or a kick-up. 
This is a type of pressed-steel construction, of channel section, and 
the deepest and strongest section is at the center where the greatest 
stresses occur. Some frames are built with a double drop, having 
a downward bend just forward of the entrance to the rear part of the 
car body, followed by an upward turn just back of the same entrance. 
The upward turn at the back is carried higher than the main part of 
the frame for the purpose of obtaining a low center of gravity. Then 
there is what is termed the bottle-neck construction, a bend inward 
which resembles that in the neck of a bottle. This obtains a short 
turning radius. Originally, frames were narrowed in front, the differ¬ 
ence in the width between the front and rear being at first an inch 
























512 


GASOLINE AUTOMOBILES 


or so on each side, gradually increasing until it became 5 and 6 inches. 
This type did not prove efficient, and the trend favored the taper 
previously explained. 

A not uncommon form of frame is shown in Fig. 375, which com¬ 
pensates for an abnormal rise of the rear axle without the possibility 
of its striking the frame. Some frames have a bend at the ends to take 
the spring fastenings. 

Pressed=Steel Frames. The pressed-steel type of frame is very 
popular with designers and is largely used on commercial cars up to 
and including 1-ton capacity. This is popular because it is the lightest 
in weight for equal strength of the structural iron or rolled channel 
and I-beam section. The cost of pressed steel is somewhat higher, 



Fig. 375. Frame of Sterns-Knight Car in Plan 


because it is heat-treated material used to obtain maximum strength. 
The cost varies with the section, material, and the nature and extent 
of bending. The finished frames are easy to handle, and the assem¬ 
bling cost is small. The channel shape is easy to brace and repair. 
These and other advantages have brought about its use. 

The cheapest construction is the straight side rail, and, when 
conditions permit, it is usually tapered at front and the rear, and the 
forward end is sometimes shaped to receive the spring hangers. 
When the side members are inswept to permit a short turning radius, 
it is necessary to make the flanges of the side rail of considerable width 
at this point, tapering gradually to the rear, to provide the proper 
strength at the point of offset. 














































GASOLINE AUTOMOBILES 


513 


Sub=Frames. The modern tendency is to eliminate the sub- 
frame a step due to the flexible mounting of the power plant and 
unit construction—because it simplifies the frame. It has also been 
made easier by the tapered frame, which is narrowest at the front 
where the units are attached. The most common method of support¬ 
ing the engine is the three-point. Sub-frames are used, however, as 
they serve the purpose both of supporting some unit and of strength¬ 
ening the frame. 

Sub-frames may be of two kinds, viz, those in which the sub- 
frame is made different for each unit to be supported, and others 
in which one sub-frame supports all units regardless of size, shape, 
or character of work. The type of sub-frame made to support each 
unit usually works out to two pairs of cross-members, one for the front 
of the unit and one for the rear; while the type which supports all 
units regardless of size works out to longitudinal members, supported, 
in turn, by two cross-members, front and rear. The added weight for 
the first-mentioned type is less than for the other, since it comprises 
only four cross-members; while the last-named type consists of two 
cross-members equal to two of the others and of two very long members 
parallel to the main-frame members, each much longer and thus 
much heavier than the corresponding cross-members. In the two 
frames already shown, Fig. 374 shows the unit type of sub-frame with 
only cross-members, while Fig. 375 shows the more modern type in 
which the power plant is of the unit type and rests directly upon the 
main frame, being the three-point suspension type in which the 
forward point is on a frame or special cross-member, while the rear 
two points are the crankcase supporting arms resting directly on the 
main frame. 

Rigid Frame. A pressed-steel or rolled-stock rigid frame has its 
advantages, particularly with reference to the commercial vehicle. 
It permits the body to be rigidly secured to it, and as it does not give 
with the inequalities of the road, the body is not racked. An advan¬ 
tage of the rolled stock is its cheapness, except, of course, for the 
lighter models of the assembled type for which frames can be secured 
at low figures. Another advantage of the rolled stock is the ease 
with which the wheel base may be altered. 

Effect on Springs. The effect of frame construction upon the 
design and duty of springs should be considered. This feature 





Fig. 376. Plan, Elevation, and Sectional Details for Chassis Frame with Narrowed Front 
Courtesy of A. O. Smith Company , Milwaukee, Wisconsin 












































































































































GASOLINE AUTOMOBILES 


515 


is not generally understood, but it has an important bearing upon the 
life of the car. A rigid frame relies upon the springs to allow for all 
axle displacement. If a front and a rear wheel on opposite sides are 
raised several inches at the same time, the frame is subjected to a, 
torsional stress. If the frame is rigid, springs of considerable camber 
must be employed in order to absorb the shock without being bent past 
the limit of safety, and they must be sufficiently flexible to absorb all 
the shock without any tendency to lift the other wheels from the 
ground. To accomplish this shock absorption, a different type of 
spring is used on a rigid chassis from that employed on a flexible 
frame. The use of underslung spring suspension has come into favor 
for this reason, as it permits the frame to be carried fairly low, without 
sacrificing spring camber or necessitating a dropped rear axle. 

The flexible frame, when diagonally opposed wheels are raised, 
does not impose all the stresses on the springs but it absorbs 
a part of them. For this reason, springs on a flexible chassis 
are flat or nearly so, with a limited amount of play. Flexible con¬ 
struction also permits the frame to be carried equally as low as with 
the underslung spring, and yet the spring is perched above the axle, 
where it is more nearly in line with the center of gravity, thus reduc¬ 
ing side sway. 

TYPES OF FRAMES 

Pressed Steel. Pressed steel is purchased in sheet form, cut to 
the proper shape in the flat, and then pressed into channel form under 
great pressure. It is made of steel rolled into sheets and is somewhat 
closer grained than ordinary steel. There is no breaking of the flake 
in the rolling process. The pressed-steel frame, as previously pointed 
out, permits of greater simplicity in assembling, since the parts can be 
easily bolted or riveted. Fig. 376 is of the type of pressed-steel frame 
having a tapering section, a kick-up at the rear end, five cross-members 
-one of them a tube—and is narrowed in at the front to give the 
largest steering lock. Otherwise it presents only standard practice. 

Wood. Wood is universal and easy to obtain. While no longer 
classed as cheap, it is not expensive; moreover, wood is kept in stock 
nearly everywhere. Users of wood for side-frame members claim 
that the wood frame is not only lighter but stronger. In addition, 
the wood frame would undoubtedly possess more natural spring and 



516 


GASOLINE AUTOMOBILES 


TABLE IV 

Comparative Strength of Steel Channels and Laminated Wood Frames 


Material 

Size 

(in.) 

Weight per 
Linear Inch 
(lb.) 

Resisting 

Moment 

Resisting 
Moment per Unit 
Weight 

Pressed Steel 

JL y 4— Y U 

16 A ^2 * 1 4 

.408 

114,830 

280,955 

Ash 

If X 6 

.266 

142,275 

534,870 


resiliency, so that it would make a lighter and easier riding frame. 
A section of a wood frame is shown in Fig. 377. 

This shows a frame made of laminated wood. There are three 
very thin sections of selected ash, marked A, which are glued together, 



Fig. 377. Section through Wood Side-Frame 
of Franklin Car 


then screwed and bolted to pre¬ 
vent the glue from opening up. 
To further this purpose, a strip B 
is fastened on the top and bottom 
in the same manner. These strips 
are laid with the grain running 
horizontally, while the main 
pieces are laid with the grain 
running vertically. This con¬ 
struction makes a very strong 
and light-weight frame; the com¬ 
parative figures for a steel sec¬ 
tion and the section shown, as 
given from the tests of the engi¬ 
neers of the Franklin Company, 
is shown in Table IV. These 
tests, which are authentic, seem 
to bear out the contention that 
the wood frame is both lighter 
and stronger than the steel frame. 

Novelty of Fergus Frame. A 
new American car, the Fergus, 
shows more novelty in frame con¬ 


struction, as well as in every other 
conceivable way, than any other. Instead of blindly following 
accepted practice in the matter of frame design and construction, the 
makers have struck out boldly along new lines. 
































































































































GASOLINE AUTOMOBILES 


517 


The Fergus car was developed as 
a result of fifteen years’ experience in 
fine repair work, and is an attempt to 
eliminate the usual “owner troubles”. 
While not intended as a “foolproof” 
car, the Fergus comes nearer being one 
than any other developed up to this 
time. In addition to actually “fool¬ 
proofing” the car, the aim of the 
makers was to eliminate much of the 
work incident to caring for the modern 
car by replacing the usual “owner- 
attention” with an automatic system. 

In the frame, a combination of 
steel girder and lattice work has been 
produced which has the appearance 
of being absurdly light. However, as 
the diagram of stresses in its members, 
Fig. 378, indicates, everything has been 
figured out with the utmost care, and 
the design has been supplemented by 
unusual workmanship. 

The complete frame, Figs. 379 and 
380, shows that a large part of the 
saving is produced by the method of 
suspending the units. Were these 
hung on the side members, as in the 
ordinary case, the frame certainly 
would not do, but as it is, they are 
hung on immensely strong brackets, 
steadied by the side members, but 
rigidly supported by large tubular 
cross-members. The brackets and 
cross-members do the work ordinarily 
assigned to the side members of the 
frame, the side members simply joining 
and holding together the various brack¬ 
ets and cross-members. 




Fig. 378. Diagram of Fergus Trussed Frame, Showing Light but Strong Construction 



























518 


GASOLINE AUTOMOBILES 


An examination of the design reveals the astonishing extent to 
which the brackets have been combined, the rear engine member, 
for instance, also acts as the rear support for the front spring, for 



the step support, and for the dash support. At the sides and rear 
there is a similar combination of functions. 

Recent Types of Frames. An innovation in frame design is the 
Marmon, shown in Fig. 381, the side rails and running boards of which 
are made in a single unit. The great width of the running board, 


Fig. 379. Forward Portion of Chassis of Fergus Car, Showing Method of Attaching Springs, Front Axle, and Engine 














































































































































520 


GASOLINE AUTOMOBILES 


varying from 11 \ to 16 inches, serves as the bottom flange of the 
frame, and is therefore of Z-section. The vertical section of the frame 
is 10 inches high, and has height enough to replace the running board 
fenders without appearing narrow. At the front and rear ends of the 
frame, the running boards are curved upward, strengthening the frame 



Fig. 381. Marmon Aluminum Frame, Showing Running Board Construction 


as well as supporting the fenders into which they merge. The frame, 
beyond these points, both forward and rearward, is made of channel 
section of the conventional type. The rear of the frame is 45 inches 
wide and tapers to 30 inches at the front spring hangers. The great 
depth of the frame section makes it very stiff, so that the body sills 



Fig. 382. Brush Pressed-Steel Frame 
Courtesy of Hale and Kilburn Company, Philadelphia, Pennsylvania 


can be entirely eliminated, and yet the doors will not work loose or 
bind when the top is up or down. 

Fig. 382 illustrates a type of frame similar to the Marmon, the 
Brush frame, controlled by the Hale and Kilburn Company, of 
Philadelphia. 













GASOLINE AUTOMOBILES 


521 


Steel Underpans. The underpan lias assumed a great deal of 
importance in the last two years, for makers have more and more 
realized that it is highly important to protect many of the parts from 
road dirt, flying stones, water, etc. Designers have, therefore, given 


Fig. 383. Two-Piece Pressed-Steel Underpan Used on Winton Cars 
Courtesy of Winton Motor Car Company, Cleveland, Ohio 

considerable attention to its shape, size, and method of attachment. 
In some types, it apparently runs underneath both engine and trans¬ 
mission and is made more or less a part of the main frame. There¬ 
fore, its quick removal on the road would be difficult, if not impossible; 
yet road accidents sometimes make it necessary for the driver to take 
this pan off to get at the lower side of engine, clutch, or gear box. 

For this reason, underpans generally resemble more closely that 
shown in Fig. 383. This is a side view, showing the semicircular 
form of the pans, as well as the two-piece construction. The forward 
part under the engine, which would be taken 
down fairly often, is held in place by three 
spring clips on either side. Lifting these 
clips off is only a second’s work; in addition, 
there is a filler piece in front, helping to make 
the pan fairly air-tight. The depth of the 
pan increases slightly toward the rear, so as 
to form a slope down which liquids will 
drain; the rear end is fitted with an upturned 
elbow, so that it will not drip until it accu¬ 
mulates a considerable quantity of liquid. 

Continual dripping indicates a full charge, 
and the pan is drained by turning the elbow 
over. 

In Fig. 384, a detail of the arrangement of the pan shown in 
Fig. 383 is presented. This indicates both the permanent part of the 
underpan, which is attached to the frame, and the removable part, 
which is freed by loosening the spring clips shown. 










































Fig. 385. Plan and Elevation of Frame of Heavy Truck 


































































































































































GASOLINE AUTOMOBILES 


523 


CommerciaLVehicle Construction. Commercial work, being 
rougher, harder, and cheaper work, changes the frame construction 
just as it does everything else about the car. In Fig. 385, a 
commercial-vehicle frame which brings out this point is shown. 
The main sills are 6-inch channels, while all of the other members 
are correspondingly large angles and channels. In one place the section 
consists of a box shape made up by bolting two large channels together, 
with the open sides in. The total overall length is not given, since 
this differs according to the variations in the wheel base; but, by a 
comparison of the figures given, it is seen that the frame shown is in 



Fig. 386. Solid Rear Construction of Locomobile for Tires and Tanks 
Courtesy of Locomobile Company of America, Bridgeport, Connecticut 


excess of 210 inches long by about 37 inches outside width. This is 
about twice the total length of the average small car. 

In the bracing and arrangement of the different members, this 
frame shows other points of difference, the cross-members, for 
instance, being nine in number, not including the two diagonal 
cross-members. The longitudinal members, too, are eight in number, 
not counting the two diagonals. 

Rear=End Changes. The locating of the fuel tank at the rear of 
the chassis—a practice that was brought into favor largely through 
the introduction of the vacuum system of fuel supply—has resulted 
in a number of changes to the rear ends of frames. The placing of 
the fuel tank at the rear is not new, and probably it would not have 















524 


GASOLINE AUTOMOBILES 


occasioned any change to the rear end of the frame were it not largely 
for the fact that the spare tires are now carried at the rear of the 
chassis. The tires themselves are not heavy enough to make it 



essential to strengthen the rear ends, but the very general use of 
carrying the spares inflated on demountable rims has added consid¬ 
erable weight to the rear of the chassis. This weight, coupled with 



Fig. 388. Typical Rear-End Construction, Carrying Gasoline Tank 


that of a large fuel tank, has compelled makers to give more attention 
to the rear construction. 

Provision is made for carrying the spare tires on the Locomobile 
chassis by means of an apron conforming in shape to the shoe. The 
three-quarter elliptic springs of the scroll type have ends attached to 
the outside of the main frame, which is carried back and serves as an 
















































































GASOLINE AUTOMOBILES 


525 


extension for attaching the fuel tank. A cross-member is also utilized; 
it serves as a point of attachment for the two rods supporting the 
lower apron and for two upper rods as well. This design has merits 
in that the tire carrier is firmly anchored and serves to protect the 
fuel tank from injury possible in operating in crowding traffic where 
rear-end collisions are not uncommon. As may be noted, Fig. 386 
shows the method of using an upper cross-member to prevent theft 
of the tires. 

A different type of rear construction is shown in Fig. 387, a Reo. 
Here the rear cross-member is gusseted, and a pair of substantial arms 
are riveted to the cross-member. These arms serve as an anchorage 
for the tire holders which, in turn, have a cross-rod for protection. 
Still another design is shown in Fig. 388. Here the side rail of the 
frame projects back of the rear cross-member of the frame for a dis¬ 
tance of about 12 inches. The fuel tank is suspended from these two 
extended frame members by means of steel straps which pass around 
the tank. 

FRAME TROUBLES AND REPAIRS 

The more usual troubles which the repair man will encounter 
are sagging in the middle; fracture in the middle at some heavily 
loaded point or at some unusually large hole or series of holes; 
twisting or other distortion due to accidents; bending or fracture 
of a sub-frame or cross-member; bending or fracture at a point 
where the frame is turned sharply inward, outward, upward, or 
downward. 

Sagging. A frame sags in the middle for one of two reasons, 
either the original frame was not strong enough to sustain the load 
or the frame was strong enough normally, but an abnormal load was 
carried, which broke it down. Sometimes a frame which was large 
enough originally and which has not been overloaded will fail 
through crystallization or, in more common terms, fatigue of the 
steel. This occurs so seldom, and then only on very old frames, 
that it cannot be classed as a “usual” trouble; moreover, it cannot 
be fixed. 

When a frame sags in the middle, the amount of the sag deter¬ 
mines the method of repair. For a moderate sag, say \ to \ inch, 
a good plan is to add truss rods, one on either side. These should 
be stout bars, well anchored near the ends of the frame and at points 


526 


GASOLINE AUTOMOBILES 


where the frame has not been weakened by excessive drilling. They 
should be given a flattened U-shape, with two (or more) uprights 
down from the frame between them. The material for them should 
be stiff enough and strong enough to withstand bending and should 
be firmly fastened to the under side of the frame. The truss rods 
should be made in two parts with a turnbuckle to unite them, the 
ends being threaded right and left to receive the turnbuckle. 
When truss rods are put on a sagged frame, it should be turned 
over and loaded on the under side; then the turnbuckles should be 
pulled up so as to force the middle or sagged part upward a fraction 
of an inch, say f to J inch, and then the frame turned back, the 
other parts added, and the whole returned to use. A job of this 
kind which takes out the sag so that it does not recur is a job to be 

proud of. 

Fracture. Many frames 
break because too much metal 
was drilled out at one place. 
Fig. 389 shows a case of this 
kind. The two holes were 
drilled, one above the other, 
for the attachment of some 
part, and were made too large. 
They were so large that at 
this particular point there was 
not enough metal left to carry the load, and the frame broke, as indi¬ 
cated, between the two holes and also above and below. A break of 
this kind can be repaired in two good ways. The first and simplest, 
as well as the least expensive, is to take a piece of frame 10 to 12 
inches long, of sufficiently small section to fit tightly inside this one. 
Drive it into the inside of the main frame at the break, rivet it in 
place firmly throughout its length, and then drill the desired holes 
through both thicknesses of metal. 

This is not as good as welding. A break of this kind can be 
taken to a good autogenous welder who will widen out and clean the 
crack, fill it full of new metal, fuse that into intimate contact with the 
surrounding metal, and do so neat and clean a piece of work that one 
would never know it had been broken. When a welding job is done 
on a break like this, and no metal added besides that needed to fill the 



Fig. 389. Reboring Cracked Steel Channel 




















GASOLINE AUTOMOBILES 


527 


crack, subsequent drilling should be at an angle, to avoid a repetition 
of the overloading condition. In the figure, the dotted lines suggest 
the drilling. By staggering the holes in this way, there is a greater 
amount of metal to resist breakage than would be the case with one 
hole above the other—a method which might preferably have been 
used in the first place. 

So much welding is done now, and so many people know of its 
advantages, that every repair shop of any size should have a weld¬ 
ing outfit. A frame job is essentially an inside bench job, but a 
large number of cases of welding could be done directly on the car 
outside the building, particularly in summer when the outside air 
and cooling breezes are desirable. So, it is well to construct a small 
truck on which to keep the 
oxygen tank, acetylene cylin¬ 
der, nozzle for working, and a 
fire extinguisher. One form 
of a truck is shown in Fig. 

390. This truck is a simple 
rectangular platform with 
casters, a handle, and a rack 
to hold the tanks. It saves 
many steps and is particu¬ 
larly convenient in summer 
months. This outfit is essen¬ 
tially a home-made affair, but 
the gas-welding and electric¬ 
welding manufacturing companies have designed small outfits espe¬ 
cially for automobile repair work, which would be preferable to the one 
in Fig. 390, especially where the amount of repair work warrants a 
reasonable expenditure for a welding outfit. A description of both gas 
and electric outfits and instructions for their use are given in the 
section on Oxy-acetylene Welding Practice. 

Riveting Frames. Tightening Rivets. Rivets securing the cor¬ 
ners of a frame or holding cross-members, gussets, and plates often 
work loose, particularly with the flexible type of frame previously 
alluded to. The location of the rivet and the accessibility of the part 
will determine how best to proceed with the work. The chief trouble 
experienced is that of placing a sufficiently solid article against the ri\ et 



Fig. 390. Handy Oxy-Acetylene Outfit 


528 


GASOLINE AUTOMOBILES 


while the other end is being hammered. As a rule, old axles, sledges, 
and hammers will serve under ordinary conditions, but these cannot 
always be used in a channel frame. One method is to employ an old 
anvil which is turned upside down and so placed in the frame that the 
flat end of the anvil is placed against the head of the rivet, while a rivet 
set is employed to set the rivet up snug. The horn of the anvil is 
allowed to rest on the other side of the frame. This method can be 
used for cutting off rivets as well as for tightening old ones. The anvil 
should be of sufficient length to rest on the frame as above described. 

When an anvil is not available, the following method may be used 
with success. Take a J-incli bolt and cut it off so that it will just go 
in the frame between the rivets. Slightly countersink the head of the 
bolt with a cold chisel. Put on the nut and slip in between the rivets 
and run the nut down until it expands tight in the frame. The 
depression in the head of the bolt, and the nut fitting around the oppo¬ 
site rivet head will keep 
it firmly in place while 
riveting. It is not always 
practical to attempt to 
tighten a rivet. The bet¬ 
ter method is to remove 
it, drill a larger hole and use a larger size rivet. Rivets are usually 
made of Norway iron. Heat to a red heat before using. 

Riveting Methods. There are two methods of riveting, the driving 
in and the backing in. The latter method is shown in Fig. 391, and 
the two plates to be riveted are drilled in the usual manner, as shown 
at A, with the rivets a trifle smaller than the hole, placed as shown 
at B. With hot riveting, the hole should be about inch larger than 
the rivet, but with cold rivets, the opening should be such that the 
rivets will slide in. Instead of backing up the head of the rivet, a 
dolly is applied to the small end, as indicated at C, and the driving 
is done on the head of the rivet by a set D and a hammer. The 
energy of the hammer is applied through the set to the rivet, which is 
upset or enlarged, as it is unable to move because of the mass of metal 
in the dolly. The metal of the rivets expands sidewise at A and B , 
completely filling the space. A feature of this method is that a part 
of the hammer blow is expended in forcing the plate N into contact 
with the plate 0. The metal at B is prevented from moving sidewise 



B 

0 

N 

/ 

CP 

f © c 



i 






Fig. 391. Method of Riveting Frame 













GASOLINE AUTOMOBILES 


529 


by & bead formed at the dolly end of the rivet, and additional blows of 
the hammer tend to bring the plates closer and to hold them. The 
backing-in method is practical in making the various styles of rivet 
heads, particularly in making the thin, almost flush, head, and an 
advantage is that there 


are no reactionary 
stresses upon the thin 
head as would exist with 



2Mnsr» 


the driven-in rivet. 

As there is more 
demanded of the rivet 
replacing the old mem¬ 
ber, it is important that 
the work be carefully 
performed. This applies 
to the holes in the plate. 

All sharp corners should 
be removed, as they af¬ 
ford an opportunity for the rivet to shear off by external stress 
or to fly off under internal strain. A reamer, drill, or countersink 
can be used in removing sharp corners. The face left need not be 
more than -§t or 3 V inch wide, in order to greatly strengthen the rivet 
at its weakest point, or where the head joins the body. By slightly 


Fig. 392. Adding a Truss Rod to the Front of a Weak or 
Damaged Frame to Strengthen It and Preserve 
the Radiator 





Fig. 393. Bracing Fractured Frame with Bar and Turnbuckle 


chamfering the corner of the plate, the rivet is given a corresponding 
fillet, which not only increases its holding power but serves to draw 
the plates together. 

Frame Bracing Methods. There are several methods whereby a 
frame that has been injured through collision or has sagged because 



















































530 


GASOLINE AUTOMOBILES 


of too light construction can be repaired. The front of the frame is 
the chief offender in this respect, and many times a leaking radiator 
is the result. When repairs to the radiator fail to cure the trouble, it 
may be assumed that the frame is at fault. A simple remedy is 
shown in Fig. 392 and consists in bracing the frame by means of a rod 
and turnbuckle. The rod should be about 2 inches longer than the 
width of the frame and threaded for about 3 inches on each end. 
The turnbuckle is not essential, but it simplifies the work. In 
installing the brace, the inside nuts are screwed on first and far enough 
to allow putting the rod in place. These nuts are next screwed out 
until they bear against the frame, and the latter is forced out until 
any pressure that may have existed on the radiator is eliminated. 
The outside nuts are then screwed up snug. The advantage of the 
turnbuckle is that adjustments may be made as required. 

Fig. 393 shows a method of trussing a frame that was fractured 
by the stresses of the motor starter. Even after the fracture had 
been repaired, the driving gear of the starter would not mesh properly 
with the ring gear on the flywheel of the engine. As the movement 
was up and down on the frame, a truss was found necessary; while it 
was a simple matter to attach one end of the truss on the left-hand side 
of the chassis, the right-hand side was more difficult because of the 
proximity of the ball arm of the steering-gear lever. The problem 
was solved by forming a loop at one end of the truss of sufficient width 
and length to permit travel of the ball arm. By utilizing a turn¬ 
buckle the desired tension was obtained. 

SPRINGS 

Basis of Classification. The springs are important components 
of the chassis; for while the frame supports the power plant, clutch, and 
gearset, it is, in turn, supported upon the springs. The tendency at 
present is to design the frame and spring suspension so that the rear 
springs are placed very close to the rear wheels. In some cases, the 
frame is wide at the rear and is directly over the springs. Springs 
may be divided into seven general classes as follows: semi-elliptic, 
the full-elliptic, the three-quarter elliptic, the platform type, the 
cantilever, the quarter-elliptic, the coil, and combinations of these. 
The full-elliptic spring is made up of two sets of flat plates, slightly 
bowed away from each other at the center and attached together at 


531 


GASOLINE AUTOMOBILES 

the ends. When these are used, the centers of the springs are attached 
top and bottom, respectively, to the frame and axle. With half of 
the top of the spring cut away, and the cut, or thick, end attached to 
the frame, this spring becomes a three-quarter elliptic. When the 
whole top of the spring is cut away, so that the spring is but a series 
of flat plates, bowed to a long radius, this becomes a semi-elliptic 
spring. By turning the semi-elliptic spring over, it becomes a canti¬ 



lever when its center and one end are attached and the load applied 
to the other end. The quarter-elliptic is but a quarter of a spring, 
while the platform consists of three semi-elliptics—two as side mem¬ 
bers in the regular position, while the third is used as a cross-spring, 
being inverted and attached at the center to the rear end of the frame 
and at its ends to the side members. The coil form requires no expla¬ 
nation and is not now used on cars. In addition, these forms are 
modified by scroll ends and various attachments. 



Semi=Elliptic. Fig. 394 shows a front spring of the semi-elliptic 
type, the form which is used now for almost every front spring. 
This is a working spring of the usual type, fixed at the front end, 
shackled at the rear end, attached to the axle in two places, and with 
two rebound clips in addition. The latter are put on the springs 
to prevent them from rebounding too far, in the case of a very deep 
drop. In some cases, as high as four, six, or eight of these clips may 


a 












532 


GASOLINE AUTOMOBILES 


be used. Many other springs are made with ears, these being clipped 
over the next lower spring plate, the final result being the same as the 
use of many clips, but with improved appearance. 

FulLElliptic. Full-elliptic springs are the oldest form known. 
Fig. 395 shows the construction of this type, the upper and lower parts 
being pivotally connected at the ends. A slight modification of this 
form, known as the scroll-end full-elliptic type, is in more extensive 



use than the full-elliptic plain type. As Fig. 396 shows, the ends of the 
upper leaves are bent over. Each carries an eye, which is connected to 
the eye in the end of the upper leaves of the lower half of the spring by 
means of a shackle. This construction makes a very soft-riding spring. 

Three=Quarter Elliptic. Very much like Fig. 396 is the form 
known as the three-quarter elliptic spring, the one having scroll ends 
being shown in Fig. 397. This form of spring is fastened at three 



points. The lower part of the spring is shackled at the front end, 
fixed to the axle at the center, and shackled to the upper part of the 
spring at the rear. The upper part of the spring is fixed to the frame at 
the upper front end and shackled to the lower part at the rear. Fig. 407 
shows another example of the three-quarter elliptic spring, which may 
differ in practice, as some three-quarter springs are not'scroll ended. 

This form of spring is growing in favor daily, a greater number 
being used this year than last, while designs for next year show a still 




























GASOLINE AUTOMOBILES 


533 


greater increase. One reason for this increase is the great increase in 
the number of dropped frames, that is, frames unswept at the rear. To 
this form of frame, the three-quarter elliptic spring is very well adapted 
and makes a very natural,very good, and very easy-riding combination. 

Platform. The platform type of spring is used a great deal on 
large cars, as well as on very heavy trucks, on account of its ability 
to carry heavy loads well, and also on account of its flexibility. 
As may be seen in Fig. 398, it consists of three semi-elliptic springs 
shackled together at the corners. The rear cross-spring is usually 
made shorter than the two side springs, while the latter are set off 
center, making the front of the spring, that is, the part forward of 
the point of attachment to the axle longer than the part to the rear. 
There are two reasons for this: First, the front end acts somewhat 
as a radius rod, the rear end of the frame rising in an arc of a circle 
whose radius is the front half of the spring; second, this plan dis- 



Fig. 398. Platform Springs, Showing How Side- and Cross-Springs Are Shackled Together 


tributes the spring action equally in front of and back of the axle. 
Since the rear cross-spring is fastened to the frame in the center, 
each half of it is considered as a part of the side spring to which it is 
shackled. Thus, the total length of the side spring in front of the 
axle is the measured length of the side spring, while the total length 
of the side spring back of the axle is considered as the side length 
plus half of the cross-spring length. The center point, or point of 
axle attachment, is not moved so far forward as to make these two 
lengths equal, but in a proportion which may be derived thus: Assume 
a side spring 42 inches long and a cross-spring 35 inches long; then the 
spring would be set out of center some 4| inches, making the front 
length about 25| inches, while the rear length would be 16J inches plus 
half of the rear spring, or \1\ inches, making a total of 34 inches. 
This would give a ratio of 25§ to 34, or 1 to 1.333. If the side mem¬ 
bers were 50 inches, the ratio would be about 1 to 1.25, and for side 
members shorter than 42, the ratio would be about 1 to 1.5. 





534 


GASOLINE AUTOMOBILES 


Cantilever. The cantilever is, in appearance, a semi-elliptic 
spring turned over. It gets its name, however, from the method of 
suspension, which is quite different from that of any form of semi- 
elliptic spring. Moreover, as a part of this suspension, at least one 



Fig. 399. Cantilever Rear Spring Used on King Cars 
Courtesy of King Motor Car Company, Detroit, Michigan 


end of the cantilever and sometimes two are finished up flat and 
square to slide back and forth in a groove provided for that purpose, a 
bolt through a central hole preventing the spring from coming out of 
its guide. One form, shown in Fig. 399, has a fixed attachment 
to the rear axle, a pivoted attachment to the frame at its center 



Fig. 400. Front End of Cantilever Spring on Siddeley-Deasy (English) Car 


(or slightly beyond the center), and a sliding attachment to the frame 
at its forward end to take care of the increase in length and of the 
forward movement necessary when the rear wheels rise. 

Another form of cantilever is that shown in Fig. 400. This is 
the rear spring on the Siddeley-Deasy (English) car and, like that of 

























GASOLINE AUTOMOBILES 


535 



the King, is pivotally mounted on the frame just forward of its center. 
Unlike the King, however, the forward end of the spring has a shackle 
which permits it to swing when the rear axle rises or falls. This 
shackle is a very interesting feature of this installation, having an 
adjustment which is most unusual for a shackle, Fig. 401. Note how the 
outsides of the shackle 
have a series of grooves, 
into which the head of 
the shackle bolt on one 
side and the washer on 
the other, fit. By setting 
these in the desired 
grooves and tightening 
the nut, the position is 
fixed. If this does not 
give the proper throw, it 
is a simple matter to re¬ 
move the nut and make 


Fig. 401. 


Detail of the Adjustable Shackle on Siddeley 
Cantilever Spring 


a new adjustment. 

In France, a form of 
double cantilever has been tried out with success; this form consists of 
a pair of cantilevers, one above the other, separated at the center by a 
carefully sized spacing block, which is pivotally attached to the frame. 
The rear ends are attached above and below the axle, while the front 



ends are attached to two fixed points. Although the ends are made 
much thinner and more flexible than those just shown, it should be 
noted that both of them are fixed. The rise and fall of the wheels 
must be taken up by the springs themselves, the pivot in the center 
simply distributing the distortion over both the front and rear halves. 

























536 


GASOLINE AUTOMOBILES 


Advantages of Cantilever . The advantages of the cantilever 
spring are the smaller unsprung weight and the reduced manufac¬ 
turing cost for a given amount of flexibility. Another advantage is 
the absence of sharp rebounds and a greater deflection for a given 
load and length of spring; it also obviates the cut in the body required 
with the three-quarter elliptic spring. When the cantilever takes the 
driving strain, the main leaf is usually stiffened and, being stronger 
sidewise, it eliminates a good deal of the side sway. With torque 
rods, the main lead may be made lighter, as the starting, the braking, 



Fig. 403. Unique Rear Spring of Marmon Cars 


and the torque act through the torque rods. Since there is more 
metal in the line to the thrust, they are especially suitable for taking 
the thrust, and not quite as efficient in taking the torque. 

Hotchkiss Drive. The adoption in 1915 of the Hotchkiss drive, 
Fig. 402, in which the rear axle is connected with the frame through 
the chassis springs only, making the springs perform the functions of 
torque and thrust, is a radical departure from previous forms. The 
objection that it subjected the springs to unnecessary strains has not 
been sustained in practice, which has shown that a slight yielding of 
the rear axle when starting and braking, by a certain flexure in the 
springs, has reduced the stresses upon the transmission members. 









GASOLINE AUTOMOBILES 


537 


In the Hotchkiss drive, the springs are rigidly attached to the rear 
axle, while the front end of the spring is secured to the frame with a 
proportionately large bolt through which the drive is transmitted. 
Users of the drive claim that it is quieter, that the car holds the road 
better, that it is more flexible, and that it avoids the road shocks 
which are transmitted through stiff torque members from the axle 
to the frame. Makers who drive through the springs and employ 
other torque members claim that they are not sacrificing flexibility in 
driving while eliminating a certain side sway and other strains preva- 



Fig. 404. Combination Cantilever and Semi-Elliptic Spring on Tractor 


lent when the springs perform the functions of the torque. In the 
Hotchkiss drive, two universal joints in the drive shaft are used. 

Unconventional Types. Marmon. A departure from conven¬ 
tional practice is the spring used on the Marmon car and shown in 
Fig. 403. It is a double-transverse construction, consisting of semi- 
elliptic springs bolted together at the center, with a curved block, or 
hard-maple cam, between them. This cam varies their stiffness, 
the spring automatically becoming stiffer as the load increases. 
Under normal load, the stiffness is about 170 pounds per inch, but as 
the springs are compressed the stiffness will reach 400 pounds. They 




























































538 


GASOLINE AUTOMOBILES 


are shackled at one side and fixed at the other, obtaining a perfectly 
parallel motion to the frame. There is said to be no roll as is some¬ 
times found with transverse springs. 

Knox Tractor. An unusual method of suspension is that 
employed on the Knox tractor, a combination of a cantilever and 
semi-elliptic spring at the rear end of the frame. The design shown in 



Fig. 405. Rear Spring of Six-Ton Truck 


Fig. 404 includes heavy semi-elliptic springs, which are attached to 
the rear axle by long clips and carry the fifth wheel of the trailer. 
There is no connection between the springs and the tractor frame, so 
they carry the weight of the trailer and load only. The tractor frame 
is mounted on a cantilever spring having a pivot near its center and a 
shackle at the front end. The rear end bears on a seat clipped to the 
rear axle. This obtains a flexible mounting for the tractor and also 
permits the carrying of very heavy loads on the trailer. 



Fig. 406. Special Semi-Elliptic Rear Springs Formerly Made for Winton Cars 
Courtesy of Perfection Spring Company , Cleveland, Ohio 


Semi-Elliptic Truck Spring. The semi-elliptic spring is a favorite 
with makers of commercial vehicles. It is simple, and if the length, 
width, and other dimensions are proportioned correctly, it is a most 
satisfactory method for both front and rear suspension. Fig. 405 
shows a rear spring for a 6-ton truck, the method of shackling, and 
how it is mounted on the axle by means of a spring seat. 




























GASOLINE AUTOMOBILES 


539 


Winton. Many makers use their own special form of springs. 
Fig. 406 shows the spring formerly used on the Winton cars, a type 
which might be described as a double-purpose spring. It was made 
in two parts, the lower part consisting of a regular semi-elliptic flat 
spring, while the upper part was a semi-elliptic flat spring with scroll 
ends. The central part of the spring was treated as one, being 
attached to the axle in the usual manner; the ends, however, had a 
peculiar appearance, because the upper and lower halves of the spring 
were of different shape. The scroll end of the upper part was sup¬ 
posed in itself to absorb many of the small road shocks. The spring 
was loosely attached to the frame at each end by means of a double 



Fig. 407. Three-Quarter Scroll Elliptic Springs on Winton Car 


shackle, made necessary by the double action of the spring; the tend¬ 
ency to flatten out increased its length, thus calling for a forward 
motion of the front and a backward motion of the rear ends, while the 
different lengthening action, owing to the difference in the lengths of 
the two parts of the spring itself, resulted in a turning about a different 
point. 

For comparison with this earlier Winton spring, the latest form 
is shown in Fig. 407. It will be seen that the three-quarter elliptic 
form has been adopted, with a kick-up at the rear end of the frame. 
If the two types are compared somewhat closely, it will be seen that 
the only change in the frame part is the kick-up. The new springs 
show the scroll ends to which Winton has always been partial. 










540 


GASOLINE AUTOMOBILES 


Ford. The form of the Ford spring has always been distinctly 
different. Fig. 408 shows the front and Fig. 409 the rear spring used 
on Ford cars, the distinction in the front spring being principally 
in the use of a single ordinary inverted front spring set across the 
frame on top of the axle, where most makers use a pair of side springs 
set parallel to the frame. This form is simple and cheap to make 
and assemble, the cost of the spring itself, and the work of putting 



Fig. 408. Special Vanadium Front Springs for Ford Cars > 

Courtesy of Ford Motor Company, Detroit, Michigan 


it on being just about half that of the spring attachment of the 
ordinary two-spring type. On the other hand, excellent riding quali¬ 
ties are claimed for it. A second distinction is that the spring is 
an inversion of the usual semi-elliptic type, the set of the spring 
being downward instead of upward. A third claim to distinction is 
in the use of vanadium steel, which, it is claimed, has a higher tensile 
and compressive strength than any other steel, and it is practically 
unbreakable in torsion. This steel is also being used in many other 



Fig. 409. Rear Springs of the Ford Car 


parts, such as crankshafts, camshafts, fender irons, frames, drive- 
shafts, etc., resulting in a very light-weight car, since the greater 
strength of the material allows the use of smaller sections for equiva¬ 
lent strength. 

The Ford rear spring has all the claims to distinction of the 
front spring, and, in addition, a hump at the center. Fig. 409 shows 
this hump clearly, the rear-frame cross-member being only partly 
shown. It will be noted that both ends of both springs are shackled, 







GASOLINE AUTOMOBILES 


541 


the construction necessitating it. These springs represent quite a 
radical departure, the success of which has been proved in actual 
practice. 

Locomobile. Fig. 410 shows the three-quarter scroll elliptic rear 
spring used on the Locomobile, also the method of shackling both ends 



•Mrl 


Fig. 410. Three-Quarter Scroll Elliptic Spring Used on Locomobile Cars 


of the spring, and the use of a considerable extension beyond the spring 
clip of the two upper leaves. Fig. 411 illustrates the Locomobile 
front springs, the upper spring being used on the 1916 model, and the 
lower one on the 1917 model. As may be noted, the later type is 
2 inches longer and also flatter, and the distance between the spring 



Fig. 411. Two Sets of Front-Axle Springs on Locomobile Cars 


bolt and eye of the shackle is less in proportion to the 1916 design. It 
was found that the jerky action and fore-and-aft pitching of the axle 
were eliminated by this construction, greatly improving the riding 
qualities of the vehicle. 

Electric Car Springs. The spring suspension of electric pleasure 
cars is similar to that of the gasoline vehicle, semi-elliptic suspension 











542 


GASOLINE AUTOMOBILES 


in front, and full-elliptic scroll-end suspension at the rear. The 
method of shackling is similar. 

Varying Methods of Attaching Springs. Springs are attached 
in many ways. For example, the one shown in Fig. 398 might be 
shackled at the front end, fixed to the axle, and fixed to the center 
of the frame at the rear, the side and cross-springs being shackled 
together. Again, the front end might be fixed to the frame, Fig. 412, 
all other connections being unchanged. Or, with either method of 
fixing the front end, the spring might be swiveled on the axle, so as 
to be free to give sidewise without changing the other properties of 
the spring. Or, with either method of fixing the front end of the 
spring, and with or without the axle swivel, the cross-spring might 
be pivoted at the central point so as to be free to turn in any direction 



Fig. 412. Special Type of Double Quarter-Elliptic Rear Spring 


about this central point. This latter method prevents binding and 
unequal spring action when one side of the frame is unduly raised 
or depressed, the solid method of fixing the rear end resulting in a 
double action on the part of one spring, owing partly to the tilting of 
the body and partly to spring action itself. With the pivot joint, the 
spring first swings about this point until a position of equilibrium is 
established, when the suppleness of the spring comes into action, the 
result being a deflection of half what it would be in the other case. 

This form of spring also is used with the spiral spring, the 
latter taking the place of the shackle between the side and rear 
members. In this position it serves two purposes: (1) as a 
connector, taking the place of and doing the work of a shackle, 
thus acting as a universal and swinging joint between the two 
springs; (2) as a shock absorber, taking up road shocks within 









GASOLINE AUTOMOBILES 


543 


its length, that is, in the coils, without transferring any of them to 
the body proper or, in case of heavier shocks, sharing with the side 
and rear springs. This, of course, is the true function of the 
springs to allow the road wheels to pass over the inequalities, 
rising and falling as may be necessary, while the body travels along 
in a straight line, level and parallel with the general course of the road. 

Under slinging. Almost any of the spring forms shown and 
described may be underslung, that is, attached to the axle from 
below. This is a quite common practice for semi-elliptic springs when 
used in the rear, but it is very uncommon for front springs. Similarly, 
full elliptics, whether having scroll ends or not, are frequently under¬ 



slung. The three-quarter elliptic form when used in the rear is 
usually underslung; the platform spring is not underslung so often. 
The cantilever and quarter-elliptic springs have been mentioned in 
connection with the underneath attachment. It should be pointed 
out that the position beneath the axle lowers the center of gravity by 
an amount equal to the thickness of the spring plus the diameter of 
the axle plus twice the thickness of the attaching means, and this, too, 
without interfering with the quality or quantity of the spring action. 
In the case of the cantilever, the effect of underslinging is to reduce the 
straightness of the spring, that is, the form when attached above 
the axle is almost straight, while the form when fastened below the 
axle is very much curvea has considerable “opening”. 






544 


GASOLINE AUTOMOBILES 


Shackles and Spring Hofns. Considerable improvement has 
taken place in the method of shackling springs, and provision is now 
made with some types of springs for the adjustment of the shackles 
and hangers as well as for renewing bushings. Reference has been 
made to the tendency of design in rear-spring suspension and to the 
underslung types. Fig. 413 shows the design employed with the 1917 
Premier, and, as may be noted, the springs are slightly diagonal, the 
front ends coming inside the frame line, while the rear ends are attached 
to goose necks of a rear extension of the frame pieces. Shackles are 
used for connecting the ends of the springs to the extensions. 

A departure from the conventional shackle is the safety double 
shackle used on the Rainer 1000-pound capacity delivery car, shown 
in Fig. 414. In addition to the main eye on the main leaf of the rear 

spring, the second leaf is extended 
and formed into an elongated eye, 
allowance being made for deflection 
under load. The eye of the leaf is 
attached to the frame by the usual 
rigid spring bolt. Additional means 
of support are furnished by clamps 
on either side of the spring, one by a 
pin through the elongated eye, and 
the other by a pin through the lower 
end of the clamp which takes in the 
third and fourth leaves. It is pointed out that in case the main leaf 
breaks the eye of the second becomes the driving eye, and should 
this break, the spring will wedge between the under pin and the 
upper part of the clamp, thus obtaining rigidity which is essential 
with the Hotchkiss method of drive. 

Although the general practice is to shackle the semi-elliptic front 
spring at its rear, a departure which places the shackle at the spring 
horn or in front is noted in the Manly truck. 

Adjusting Spring Hangers. The type of front-spring hanger, 
shown in Fig. 415, is adjustable. This adjustability is accomplished 
by relieving the body of the grease cup and screwing in the slotted 
bolt which eliminates side play. The grease cup body acts as a lock 
nut. The rear hanger of the front spring, Fig. 416, is adjusted by 
loosening the inside lock nut and the body of the grease cup. After 









GASOLINE AUTOMOBILES 


545 


removing the cap of the grease cup, the hanger bolt is turned out, or 
to the left, with a screwdriver, decreasing the distance between the 
links. The grease-cup body and lock nut are then set up tight. 



Fig. 415. Section of Adjustable Front-Spring Hanger 


f hong, 


er Botl 


C~o~) 


Provision is made with some types of rear springs for eliminating 
play when the rear ends are mounted on seats. 

Spring Lubrication. All springs now are fairly well lubricated. 
All shackles are provided with grease cups, and other points of attach¬ 
ment to the frame are provided with oil holes. Where the springs are 
pivoted either on frame or axle, a big grease cup is usually furnished. 
Tn addition, it is now realized that the maker can prevent much of 
the noise formerly coming 
from dry and perhaps rusted 
steel spring plates working 
over each other. There are 
several ways in which oiling 
is accomplished. The springs 
are made with an internal 
lip, or groove, which is filled 
with lubricant when they are 
assembled; or between each 
pair of spring leaves is placed 
an insert having a series of oil pockets throughout its length, each 
filled with lubricant normally held in by means of a membrane cover; 
the movement of the spring plates and the heat generated thereby 



dD'-':: 



Fig. 416. Section of Rear-Spring Hanger 












































54G 


GASOLINE AUTOMOBILES 


starts the lubricant flowing to all parts. An even later method is 
the attachment of external cups, provided with a wick which goes 
around the spring leaves and is pressed against their sides. The 
wick is kept wet with lubricant from the cups, and the motion of 
the spring leaves, together with the capillary action in the wick, 
draws the oil in between the leaves. 

Spring Construction and Materials. A study of the illustrations 
used will show that practically all modern springs are clipped together, 
the number of these clips varying with the length of the spring and the 
use to which it will be subjected. Thus, Winton, Fig. 407, shows 
three clips and a band. Some springs show as many as five clips and 
two bands. But none indicate the use of spring ears—very small pro¬ 
jections on the ends of the leaves—which are bent over the edge of the 
leaf next below it to assist in holding the spring together, but they 
are in quite general use. Altogether, there are about 14 or 15 forms 
of spring-leaf ends, but those in general use may be reduced to seven. 
These are: the oval; the round point; the short French point, a modi¬ 
fication of the oval; the round end with slot and bead; the ribbed 
form, widely used on motor trucks; the square point tapered; and 
the diamond point. 

In addition, sizes have been standardized in America to the 
extent that only five widths are used for pleasure cars and seven for 
motor trucks. Those for the former are: 1J, If, 2, 2J, and 2\ inches; 
for the latter: 2, 2\, 2§, 3, 3^, 4, and 4J inches. 

As the automobile business has called for better stand-up 
qualities under more severe conditions of use, the quality of steel 
used has been greatly improved, and other materials are better. The 
French make excellent springs, many of our best automobile manu¬ 
facturers going abroad for their springs for this reason, but American 
springs are improving in quality so rapidly that this is becoming 
unnecessary. Formerly, all springs were of a plain carbon stock, but 
now a great deal of silicon, manganese, and vanadium steel are being 
used. Some chrome and chrome-nickel steel have also been tried. 

SPRING TROUBLES AND REMEDIES 

Usual Spring Troubles. Lubrication. The average repair man 
is likely to have more call to lubricate the leaves of a spring than any 
other one thing in connection with springs. True, they lose their 


GASOLINE AUTOMOBILES 


547 


temper; they sag and show signs of losing their set; plates break in the 
middle, at the bolt hole, and near the ends of the top plate; and inside 
plates break in odd places. But more frequently the springs make an 
annoying noise, a perceptible squeak, because the plates have become 
dry and need lubricating. When this happens, and the up or down 
movement of the car rubs the plates over each other, dry metal is 
forcibly drawn over other dry metal with which it is held in close 
contact; naturally, a noise occurs. 

To lubricate the spring, it is well to construct a spring-leaf 
spreader. Of course, the job is best done by jacking up the frame, 
dismounting the spring entirely, taking it apart and greasing each 
side of each plate thoroughly with a good graphite grease, then 




Fig. 417. Handy Tools for Spreading Spring Leaves to Insert Lubricant 

reassembling it, and putting it back under the car. This is the best 
way, but it costs the most, and few people will have it done. Some- 
times spring inserts are used; these are thin sheets of metal of the 
width and length of the spring plates, having holes filled with lubri¬ 
cant over which is a porous membrane. 

For the ordinary spreading job, the plates must be pried apart 
and the grease inserted with a thin blade of steel, for instance, a 
long-bladed knife. To spread the leaves, jack up the frame so as 
to take off the load, then insert a thin point and force it between a 
pair of leaves. In Fig. 417, two forms of tools for making this forcible 
separation are shown. The first is a solid one-piece forging with 
the edges hardened. It is used by sliding the edges over the ends 
of the spring leaf, then giving it a twist to force it in between them, 
























548 GASOLINE AUTOMOBILES 

f 

as shown in the figures. The second tool is intended to be forced 
between two plates by drawing back on the handle. 

Tempering or Resetting Springs. When springs lose their 
temper or require resetting, it is better for the average repair man 
to take them to a spring maker. Tempering springs is a difficult job, 
as it requires more than ordinary knowledge of springs, their manufac¬ 
ture, hardening, annealing, etc. When springs are in this condition, 
they sag down under load and have no resiliency. If a great many 
springs are handled, a rack like that shown in Fig. 418 is well worth 
making. 

Broken Springs. When springs break, there is but one shop 
remedy—a new plate or plates. But when they break on the road, 
it is necessary to get home. When the top plate breaks near the 



shackled end, repair this sufficiently to get home by using a flat wide 
bar with a hole in one end big enough to take the shackle bolt; bolt 
this bar to the spring in place of the end of the leaf which is broken. 

General Hints on Spring Repairs. As a rule, a break in a plate 
takes place where it does not prevent operating the vehicle, but it 
should be borne in mind that the damage to the plate subjects the 
other plates to extra work, and, unless the broken member be properly 
repaired or replaced, the others are likely to break. If one of the 
intermediate plates breaks in the center at the bolt, tighten the spring 
clips as much as possible. Very frequently the rebound clips will be 
found to be loose, and missing clips also contribute to spring breakage. 

The removal of a plate from or addition to a set is very likely to 
upset the grading of the construction. It is not practical to replace a 
broken plate with a new one because it is of the same width and thick- 



















GASOLINE AUTOMOBILES 


540 


ness, but an expert spring maker should be called in to see that the set, 
or fit, is correct. The fitting of a leaf requires the services of an 
expert spring man; while it appears to be a simple matter, the lack 
of knowledge by some claiming to be spring experts is responsible for 
breakage after the spring has been repaired. The spring clips and the 
nut of the center bolt should be kept tight. The importance of 
preventing the accumulation of rust on the leaves and of lubrication 
has been commented upon. 

SHOCK ABSORBERS 

Function. The ordinary flat-leaf springs of any of the types 
previously described are inadequate for automobile suspensions. 
When the springs are made sufficiently stiff to carry the load properly 
over the small inequalities of ordinary roads, they are too stiff to 
respond readily to the larger bumps. The result is a shock, or jounce, 
to the passengers. When the springs are made lighter and more 
flexible in order to minimize the larger shocks, the smaller ones have 
too large an influence, thus keeping the body and its passengers in 
motion all the time. These two contradictory conditions have created 
the field for the shock absorber. 

The shock absorber is generally a form of auxiliary spring, the 
function of which is to absorb the larger shocks, leaving the main 
springs to carry the ordinary small recoils in the usual manner; in 
short, to lengthen the period of shock. This is done in a variety of 
ways, and, as might be expected, by a great variety of devices. 

General Classes of Absorbers. The simplest forms of absorbers 
are the ordinary bumper, or buffer, of rubber and the simple endless 
belt, or strap, encircling the axle and some part of the frame and 
acting as the rubber pad does—simply as a buffer. There are the 
following classes of the more complicated shock-preventing and shock¬ 
absorbing devices: (1) frictional-plate or cam, in which the rotation of a 
pair of flat plates pressed together tightly—one attached to the frame, 
the other to the axle—opposes any quick movement of the two or of 
either one relative to the other; (2) a coil spring used alone and in 
combination—alone it is used in the plane of the coil, or at right 
angles to it, and parallel to the center line about which the coil is 
wound, while in combination it is found joined with the simple leather 
strap or with another coil spring of equal or sometimes of less 



550 


GASOLINE AUTOMOBILES 


strength, in the latter case the weaker one acting with the main 
springs; (3) the flat-leaf spring, a more simple description of which 
would be a small duplicate of the main semi-elliptic spring set on it so 
as to oppose its action; (4) the air cushion; and (5) the liquid device, 
in simple form and in combination with some one or more of the coil¬ 



spring forms. 

FrictionaLPlate Type. A frictional-plate type of shock absorber 
is shown in Fig. 419. This absorber consists of an upper arm attached 
to the frame, having at its outer end a frictional plate in contact with a 
similar plate at the upper and outer end of the other arm pivoted to 

the axle. The two plates are 
pressed together by means of the 
nut shown in the center; this nut 
is resisted by the spring beneath 
it and the slightly arched surfaces 
of the plates. When a sudden 
bump raises the axle, it must 
turn the two faces of metal across 
each other to the limit before it 
can lift the body. As will be 
seen, this means a considerable 
distance, and it can be made 
relatively greater by clamping the 
nut up tighter, thus increasing the 
friction between the surfaces, and, 
therefore, requiring greater force 
to turn them. Because of this 
adjustable quantity of friction, 
this type is called the governed friction type. 

When cams are used, practically the same result is obtained, 
except that the device is necessarily more complicated. The cam 
action usually generates some heat, and, for this reason, this form 
of shock absorber is most always enclosed, and the interior, where 
the cam works, is filled with grease or very heavy oil. 

A modification of the plain frictional-plate form is seen in Fig. 
420, which is called a passive range absorber, because, for ordinary 
movements of the springs to which it is attached, it does not come into 
action. When the usual spring action is exceeded, however, as in a 


Fig. 419. Hartford Governed Friction Type 
of Shock Absorber 

Courtesy of Hartford Suspension Company, 
Jersey City , New Jersey 




GASOLINE AUTOMOBILES 


551 




Fig. 420. Laporte Passive Range Friction Type of 
Shock Absorber 

Courtesy of Charles Laporte, Detroit, Michigan 


sharp jounce, the device becomes effective. It appears much like the 
Hartford just shown, but the construction is decidedly different. 
The upper, or frame, arm is threaded to receive an Acme-threaded 
screw, which is carried by the lower, or axle, arm. The action of 
screwing this out tends 
to force the plate on the 

lower arm, which must \ Nk 1 

move outward with the 
screw against a rubber 
washer held firmly by the 
outside nut and cover 
plate. Thus, the scissors 
action of the two arms 
on a sudden movement is 
resisted by the compres¬ 
sion of the rubber washer. 

This compression can be 
increased or decreased by tightening or loosening the slotted outside 
nut, so that the screw is given less or more movement. The rubber 
washer is made with a series of holes in it to allow of compression. 

Coil Springs, Alone and in Combinations. Springs Alone. 
The coil-spring absorber is probably the most widely used form, 
primarily because it is 
both good and cheap; 
furthermore, it is simple 
and adds little weight. 

In most instances, the 
coil is so placed as to 
compress along the direc¬ 
tion of its center line. 

One device, however, the 
Acme, shown in Fig. 421, 
works at right angles to 
this. It consists of a pair 
of coils, the two ends of each being so constructed as to go on the 
ends of the shackle bolts in place of the usual shackle. When the 
shackle is removed, one pair of ends is fastened to the spring in 
place of the shackle, while the other pair of ends is fixed to the frame 






. 




=i -> - 



Fig. 421. 


Acme Torison Spring Fitted to Three-Quarter 
Elliptic Gears 

Courtesy of Acme Torsion Spring Company, 

Boston, Massachusetts 























552 


GASOLINE AUTOMOBILES 




or the other part of the spring, as the case may be. Note that this 
arrangement brings one of the coils on either side of the main spring 

end, extending away from 
it in a horizontal plane. In 
this position, the torsion 
spring acts as a spring 
shackle, absorbing the 
jounces and bounces so that 
they do not reach either the 
body, the attaching point, 
or the other half of the 
spring, as the case may be. 

Fig. 422 is a simple 
coil spring of barrel shape, 
that is, the end coils are 
smaller than those in the 
center and are set between 
frame and axle in such a 
way that they absorb the jounces directly. 
This is probably the simplest possible 
shock-preventing device, consisting only of 
the spring and its top frame and bottom 
axle connections. These are made in four 
of wire, varying from tg inch up 


Fig. 422. Sager Equalizing Springs Are Very 
Simple in Construction 

Courtesy of J. H. Sager Company, Rochester, New York 


'U»NO| 


sizes 


to if inch. 


In the Iv-W road smoother, shown in 
Fig. 423, the action of the spring is opposed 
by an air chamber at the top, creating a 
balance. A shock which causes the spring 
to move is opposed by the spring itself, 
while the rebound, or reaction, is opposed 
by the air compressed in the air chamber. 

Combinations . Probably exceeded in 
simplicity only by the two forms just shown 
is the type in which a coil spring and leather 
band, or strap, are combined. One of these, 
the Hoover, is shown in Fig. 424. It will be 
seen that the spring end is fastened to the body, while the strap is 


Fig. 423. K-W Spring Type of 
Road Smoother 







GASOLINE AUTOMOBILES 


553 




attached to the lower end of the spring and encircles the axle. Hence, 
this will not interfere with upward movements of the axle, but 
only with the downward ones, that is, the axle is free to rise, but as 
soon as the car body starts to rise, the 
strap-spring combination acts to prevent 
it. This is particularly true if the axle 
has reached the limit of its motion and 
has started downward before the body 
starts upward. In that case, the body 
can move upward only the amount of 
slack in the strap plus the give of the 
spring, but minus the amount the axle 
has already moved downward. This inex¬ 
pensive arrangement has found great 
favor on small cars. * rig. 424 . Hoov er Shock Absorber, 

t\ i 7 n *7 o rr T • a Spring and Strap Combination 

Double-Coil bpTlflCI lypes. In prin- Courtesy of H. W. Hoover Company, 
. i.i p , • • ■ t rv Vew Berlin, Ohio 

ciple, the use 01 two springs is not dmer- 

ent from the use of one. For structural reasons, however, it is easier 
to attach the two-spring form, while dividing the load up into two 
parts allows of the use of 
smaller diameters and smaller 
sizes of wire, thus making the 
device appear more compact. 

One of the two-spring forms, 
the J.H.S., is shown in Fig. 

425. It consists of a pair of 
cylinders with coil springs 
within. The tops of the two 
cylinders are joined by a pin, 
and this joining pin is attached 
to the lower leaf of the spring. 

Inside the cylinders, pistons 
are set above each spring, and 


these are connected, this con¬ 
nection being used for the 
other half of the spring. At the bottom, the external bands on 
each of the two cylinders are connected, so as to keep them parallel 
at all times. Thus any movement upward of the lower part of the 


Fig. 425. J.H.S. Shock Absorber Has 
Twin Springs Encased 










554 


GASOLINE AUTOMOBILES 


main-leaf spring tends to draw the enclosure for both shock-absorbing 
springs upward. The springs themselves resist this and absorb 
a large part of the movement both in force and distance. 

Flat=Plate Recoil Springs. The third class, or flat-leaf spring, 
is a semi-elliptic unit in miniature. It is placed upon the top of the 
ordinary semi-elliptic spring, but it is reversed and has a spacing 
plate between the two. The object of this plate is to prevent recoil 
and to eliminate the rebound of the car body without restricting the 
flexibility of the main springs. As shown in Fig. 426, the Ames 
equalizing spring is constructed along these lines. As will be noted, 
this allows all downward movement of the spring, having no influence 
thereupon; but when the recoil, the upward equal and opposite 
reaction, comes, the smaller upper spring opposes this reaction and 



Fig. 42G. Ames Equalizing Spring Is a Simple Small Inverted Semi-Elliptic 
Courtesy of Clarence N. Peacock and Company, New York City 


minimizes it, so that little or none of it reaches the body or the 
passengers. 

Air Cushion. Perhaps the most complicated form of shock 
absorber—certainly the most expensive and at the same time the 
most efficient—is the air cushion. This form consists of a pair of tele¬ 
scoping cylinders one being attached to the frame and the other to the 
spring. When road obstructions cause the spring to rise, it pushes its 
cylinder upward, but this movement is resisted by the air inside of the 
cylinders. With the amount of air properly proportioned to the size 
and weight of the car and its load, all this upward movement will be 
absorbed and none will reach the body and its occupants. 

This rough outline describes the Westinghouse air spring, shown 
in cross-section in Fig. 427. In order to handle the air pressure and 
keep the cylinders within the commercial limits, oil also is used in 
the cylinders. This reduces the volume of contained air; but, for 
each inch the device is compressed, the air is reduced by a greater 
percentage of its original volume, consequently the resistance to 
compression is greater than it would be without the oil. 















GASOLINE AUTOMOBILES 


555 


In the drawing, A is 
the upper section of the 
cushion chamber, telescop¬ 
ing into the lower section 
made up of tube B and 
crosshead E. The outer 
tube C is simply a guard. 
A steel casting D is bored 
out to form a guide for the 
outer tube and crosshead, 
and has a rectangular pad 
F machined for bolting the 
whole device to the bracket 
attached to the frame of the 
car. A shackle G is fastened 
to the end of the car spring / 
and is pivoted to the cross¬ 
head E. Packing ring H is 
used to make the inner cyl¬ 
inder a tight fit in the outer 
casing. A breather J is 
placed on the side, through 
which air is drawn by the 
upward movement of tube 
B through the medium of 
the tightness of packing ring 
H, just mentioned, and this 
air, on the downward move¬ 
ment, is forced through the 
passage K to a port partly 
surrounding the tube B. 
There is no packing ring 
between this tube and its 
guide D, so the air blows 
out and keeps the contact¬ 
ing surfaces clean. A fur¬ 
ther protection is afforded 
by the felt-wiper ring L, 



Fig. 427. Section through the Westinghouse Air Spring, Showing Construction and Operation 
Courtesy of Westinghouse Air Spring Company, Pittsburgh, Pennsylvania 








































































556 


GASOLINE AUTOMOBILES 


which retains the grease in the groove just above it. 0 is a rod con¬ 
necting the two front or rear springs. At the top is the screw 
cap M, covering the air valve N, which is designed to be used just 
as the air valve in a tire. 

The lower part of the device is filled with oil up to a level which 
approximates the line Z, all above this level being air under pressure. 
Consequently, the device actually compresses the air through the 
medium of the oil, which is incompressible. This oil forms a seal for 
the air chamber and prevents its leakage, although the oil itself is 
allowed to leak through, this leakage being pumped back auto¬ 
matically by the action of the springs. This works out as follows: 



Fig. 428. Westinghouse Air Springs Applied to the Rear of Pierce Limousine 


In what might be called the piston, although it is not, because it does 
not move—the other parts moving relative to it—there is the plain 
leather packing ring P and the cup leather R held out against the 
sides of the cylinder by the conical ring and spring. 

The small amount of oil which does leak past the packing rings 
P and R is caught in the annular chamber S, whence it flows down 
through the vertical (dotted) passage Q into the chamber just below 
the ball valve T. In the center is a hollow plunger U of a single- 
acting pump. This has two collars on its upper end V and W and 
between them a disc X. This almost fills the passage just above it. 
The plunger is held down by the light spiral spring shown pressing 
on the collar V. 











GASOLINE AUTOMOBILES 


557 


When a road obstruction is met and the spring rises, crosshead 
E rises and the upward movement of the oil takes the disc X upward 
until it strikes and carries with it collar V, which lifts the plunger and 
draws in a charge of oil. When the air compressed in the upper 
chamber of the device expands, and the car spring I and crosshead 
E go down again, the oil flows in the opposite direction, carries disc 
A down against collar W , and forces the plunger downward. Then 
the oil passes the ball check Y , goes through the hollow plunger, and 
is discharged back into the upper, or air, chamber. In the first place, 
the oil is put in by taking off cap M and taking out the air valve N. 
Then a special single-acting oil gun is used to force it in, a long nozzle 
being necessary to reach down into the interior, with a stop to limit 
this downward distance. The maker recommends that an excess be 
put in and then slowly drawn off to the right level. 



As will be seen from the foregoing, this device is essentially an 
air spring, and the air cushion does the work; but it is the oil below 
it, with its permissible leakage and with a pump to return this leaking 
oil, which makes this device practicable. To show the exterior, 
the part which most persons would see and remember, Fig. 428 
is presented. This figure shows the rear end of a Pierce limousine 
equipped with a pair of the Westinghouse air springs. Note the 
breather, tie rod, cap at the top, cast guide at the bottom, and other 
parts previously shown and described. 

Hydraulic Suspensions. The majority of the hydraulic devices 
developed as shock absorbers consist of turning vanes connected to 
the axle or spring, enclosed in a liquid-tight case filled with some heavy 
oil. There is a hole of small diameter in the case which connects the 
two sides of the vane, its motion forcing the fluid through this hole. 















































558 


GASOLINE AUTOMOBILES 


Thus the spring action simply pumps the oil from one side of the vane 
to the other and back again, the resistance to the flow of the liquid 
past the vanes and through the small hole absorbing all of the shocks. 

Overload Springs. Overload springs are utilized with com¬ 
mercial vehicles and may be of either the leaf or coil type, and so 
arranged as to act only when the load on the main springs reaches a 
certain weight. The wear plate may be a separate platform, as 
shown in Fig. 429, or it may be formed integral with the pressure 
block. Where coil springs are used, they are made of square section, 
attached either to the frame cross-member or to the axle. Two such 
springs are used, one on each side. The design in Fig. 429 is a semi- 
elliptic. It is attached to a frame cross-member, and the ends are 
free so that they may make connection with a separate spring seat 
or a pad on the pressure block of the side spring when a predetermined 
load has been applied. With some trucks the front springs are 
mounted on a seat forged integral with the axle and are retained by 
box clips; a coil spring is attached to the pressure block, which acts as a 
bumper. Under excessive deflections these springs strike the bottom 
flange of the frame and arrest the rebound motion of the vehicle 
spring. The Jeffery Quad employs a spring bumper which is made 
of flat metal and is termed a volute spring. It is attached to a bracket 
fastened to the pressure block. 

SUMMARY OF INSTRUCTIONS 
STEERING 

Q. Which wheel travels farther on curves and why? 

A. The outer wheel must travel much farther on any curve, or 
turn, because it is turning through an equal angle on a curve of much 
longer radius. On very short turns, the distance the outer wheel 
must travel can be more than 50 per cent greater, or longer, than that 
of the inner. 

Q. What general condition exists which makes the problem 
of steering so complicated to lay out? 

A. The answer to the previous question gives an idea of the 
demands on the steering gear. The difference in the distances which 
the two wheels must travel on all curves—some differences being as 
high as 50 per cent, and with the difference shifting from one side to 
the other—is the general difficulty. 


GASOLINE AUTOMOBILES 


559 


Q. How does the usual steering arrangement care for this? 

A. By having the linkage which connects and steers the front 
wheels arranged so that a prolongation of the center lines of the two 
steering arms will pass through the center of the rear axle. 

Q. How does this solve the difficulty? 

A. When this arrangement is used, any swing or turn given to 
the steering system, say a turn to the right, will swing the left-hand 
knuckle through a larger angle than the right, although the two are 
connected together by linkage. This means that the inner, or left, 
wheel will swing about a shorter radius than the outer, or right, wheel, 
since if the two were turned through equal angles, the two radii would 
be equal. 

Q. What other items complicate this steering problem? 

A. The fact that the wheels themselves must toe in slightly at 
the front in order to steer easily and hold a straight line when set 
straight. Furthermore, the wheels must be set with their tops wider 
apart than their bottoms so that the line through the center of the 
plane of the wheel strikes the cambered, or raised, road surface at a 
right angle; this makes the whole situation even worse. 

Q. Is the ordinary front axle of such a design that it gives per= 
feet steering? 

A. No. But it represents a working approximation which could 
not be improved upon without many needless complications. On a 
sharp turn, probably one wheel is dragged around the curve for a 
small portion of its length, but the distance is so small that it would 
never be noticed by the eye nor discovered in any difference of life 
in the tires. 

Q. How is the turning of the steering knuckles about their 
pivots obtained? 

A. The swinging movement of the steering knuckles is obtained 
through a fore-and-aft movement of the steering rod connected up to 
one of the steering-knuckle arms by a ball joint. 

Q. How is this longitudinal movement of the steering rod 

obtained? 

A. By a fore-and-aft swinging of the steering arm attached to 
the steering gear. 

Q. How is this fore=and=aft movement of the steering arm 
produced? 


560 


GASOLINE AUTOMOBILES 


A. By the partial rotation of the gear within the steering gear 
itself. 

Q. And how is this partial rotation of the gear developed? 

A. By the turning of the hand wheel, which turns the worm. 
The hand wheel is fastened to the upper end of the steering post 
proper (as distinguished by its stationary brass cover), while the 
worm is fixed to the lower end of it. Consequently, whenever 
the hand wheel is turned, the worm must turn also. 

Q. Why are the worm and the gear used for steering gears? 

A. The worm is used to secure irreversibility, as it is one of the 
few forms of mechanism which will not transmit power back through 
the entire group in the reverse direction, that is, it will not allow a 
movement of the wheels to be transmitted back to the steering wheel 
against the driver’s wishes. In addition, it is compact, noiseless, easy 
to care for, wears little, and is highly efficient. 

Q. What other forms of mechanism are used for steering gears? 

A. Bevel gear, screw-and-nut, double screw, worm gear and 
full gear as distinguished from worm gear and partial gear, spur 
gear, simple bent lever, and other forms. 

Q. What are the disadvantages of these forms? 

A. With the exception of the worm and full gear, all are wholly 
or partially reversible, so if the front wheels strike an obstacle, the 
shock is transmitted back to the driver’s hands. 

Q. How are steering wheels made? 

A. In various ways. Some are rings of glued-up wood, to the 
underside of which the arms of the steering-wheel spider are fastened. 
Others have the arms cast integral with the aluminum rim; still others 
are of bronze with a molded rubber surface applied to the bronze ring. 

Q. Is the wood form, with spider fastened to it, popular? 

A. It was, but it is rapidly going out in favor of something 
better. This construction is now used only on the cheapest cars and 
not on all of those. 

Q. What are the advantages of the hinged, or folding, steering 
wheel? 

A. Folding up the wheel out of the way allows the driver to get 
out on the lever side of the car, which might be practically impossible 
otherwise. It allows stout drivers more comfort in getting in and out. It 
is also an advantage when working in the front compartment of the car, 


GASOLINE AUTOMOBILES 


561 


Q. What is the importance of the cross=rod at the front axle? 

A. It is the only member tying the two steering knuckles 
together. If this rod is bent, the wheels cannot be steered accurately; 
if it is broken, they cannot be steered at all. In fact, the car cannot 
be moved forward when the rod is broken. 

Q. Why is the rod usually placed behind the front axle? 

A. As a protection against damage from high spots in the road. 
If it is back of the axle, it is well protected; but if the design places 
the rod in front of the axle, it has no protection, and trouble is likely 
to ensue on rough roads. 

Q. Where is the front end of the steering rod carried? 

A. As a similar means of protection, the steering rod is fre¬ 
quently carried over or above the front axle, so that the axle will 
protect it. Even when the design of axle, steering knuckle, and other 
parts necessitates this rod being below, it is placed as close as possible 
to the axle level, so as to get the maximum protection. 

Q. What is the function of the steering knuckle? 

A. It forms a pivot, or bearing, upon which the front wheel 
rotates; but, in addition, it forms the basis of steering, being capable 
of turning about a vertical (or nearly vertical) axis. 

Questions for Home Study 

1. Describe the complete steering mechanism of the Pierce- 
Arrow car. 

2. Why is it better to steer with the front wheels than with the 
rear wheels? 

3. Tell in detail how a worm and sector mechanism works. 

4. Describe the working of a worm and nut device. Is it better 
than a worm and gear and if so, why? 

5. How is the Gemmer steering gear adjusted (a) for wear of 
the worms; (b) for looseness of the steering wheel? How is it 
lubricated? 

6. Describe the Hindley worm. What are its advantages; 
disadvantages? 

7. Select and describe one form of steering-wheel construction. 

8. How would you adjust a steering rod for (a) length; (b) 

wear? 

9. Tell the advantages and disadvantages of the various possible 
positions for the cross-rod; for the steering rod. 





562 


GASOLINE AUTOMOBILES 


FRONT AXLES 

<• 

Q. What are the usual front=axle classes? 

A. Eliminating freak forms, axles are generally divided into 
five classes: Elliott; inverted or reversed Elliott; Lemoine; front 
drive; and fixed axle, or fifth wheel, form. 

Q. What is the nature of the Elliott front axle? 

A. The Elliott form has the end of the axle in the form of a jaw, 
or Y, with a bearing above and one below the steering knuckle. The 
latter fits in between the two parts of the jaw, or Y, and consequently 
has a single central bearing. 

Q. How does the inverted Elliott differ? 

A. In the inverted, or reversed, Elliott form, the axle end is made 
with a single central bearing, while the knuckle takes the form of a jaw, 
or Y, and has the two bearings, one above and one below the axle end. 

Q. Which of these two forms is the better? 

A. There is little choice, but what there is seems to favor the 
Elliott form because it gives a stiffer and better bearing in the axle end, 
which is generally a good size rigid member. In fact, the axle ends 
can be made large enough in this form to have ball, roller, or other 
anti-friction bearings. This is not true with the reversed form. 

Q. How is the Lemoine axle constructed? 

A. The steering knuckle and its pivot are integral and form a 
letter L. The axle end is plain and forms a single bearing on the upper 
end of the steering pivot. In the regular Lemoine form, the L has 
its vertical leg extending upwards, and the axle is on top of the knuckle, 
so to speak. As constructed in LTnited States the vertical leg of the L 
is turned downward, so that the axle is below the knuckle 

Q. What are the advantages of this form of construction? 

A. Both axle end and knuckle are simplified and can be con¬ 
structed more cheaply. Moreover, the complete axle can be assembled 
or disassembled more readily and quickly. Some consider that this type 
has a nicer, cleaner appearance and thus improves the front of the car. 

Q. What is the disadvantage of the Lemoine type? 

A. The principal disadvantage of the Lemoine axle, ascom pared 
with other forms, is the difficulty of suitably handling the bearing 
loads. The ordinary axle has separate radial-load bearings and 
thrust washers or thrust bearings. In the Lemoine the axle-end bear¬ 
ing must handle both radial and thrust loads, as well as road shocks, 


GASOLINE AUTOMOBILES 


563 


Q. What are the usual axle materials? 

A. Modern practice restricts front axles to hand- and drop- 
forged steel, to tubular centers with forged ends, and to pressed steel. 
The latter is little used, however. Cast steel and manganese bronze 
as well as wood, have been used. 

Q. What are the usual axle bearings? 

A. Ball, roller, and plain bearings are widely used. For the 
sake of simplicity and compactness, the steering-pivot bearings are 
often plain, while the wheel bearings on the knuckle end are about 
evenly divided between ball and roller. Thrust bearings are about 
evenly divided between plain steel bearings with bronze washers, on 
the one hand, and with ball bearings, on the other. 

Questions for Home Study 

1. Describe a good method of truing front wheels. 

2. How would you determine that front wheels were out of 
alignment? 

3. Describe in detail the (a) Overland front-axle; (b) the 
Christie; (c) the Marmon. 

4. How are axles lubricated, with reference to (a) wheel bear¬ 
ings; (b) steering pivots; (c) thrust washers or thrust bearings? 

5. What are the disadvantages of cast front axles? 

6. Are ball bearings better than roller bearings for front-axle 
pivots and if so, why? 

7. Describe in detail the process of straightening a bent front 
axle. Would you use a template and if so, why? 

FRAMES 

Q. What is the need for a frame in an automobile? 

A. Every automobile needs a frame, stiff and strong enough to 
support all the units for power development and use, down to the 
springs. 

Q. Is there any radical difference between pleasure=car and 
motor=truck frames? 

A. None, except that the truck frame must carry a much heav¬ 
ier load and, therefore, needs to be stiffer and stronger and that it 
must cost less relatively, thus necessitating a form or shape which is 

cheaper to construct. 

Q. What materials are used for frames? 


564 


GASOLINE AUTOMOBILES 


A. Principally steel and wood. Steel is divided into rolled, 
used mainly for trucks; and pressed, used for pleasure cars and for 
the smaller trucks, or delivery wagons. Wood is divided into plain 
straight wood, laminated wood, and wood used as a filler for steel. 

Q. Is wood used at all widely? 

A. No. With the exception of Franklin, using laminated wood, 
and of a few light cars and light trucks which have a wood filler inside 
of a pressed-steel frame, wood is used very little. 

Q. Is steel tubing used for frames? 

A. Frames are no longer constructed entirely of tubing, although 
this has been tried, but some designers use tubular cross-members 
for the support of the engine, the transmission, and other units. 

Q. Is structural steel widely used? 

A. For pleasure cars very little, if at all; for trucks quite freely, 
but in gradually decreasing quantity. Frame makers are producing 
better and cheaper frames of pressed steel each year, gradually elimi¬ 
nating any and all arguments in favor of rolled or structural steel. 

Q. What is a frame “kick=up”? 

A. When the rear end of a frame otherwise fairly straight and 
level is bent sharply upwards from two or three to as much as ten 
inches, beginning just forward of the rear axle and carried out to the 
rear end of the frame on this higher level, this whole raised rear end is 
called a kick-up. 

Q. What is the purpose of a kick=up? 

A. It lowers the central part of the chassis relatively, thus giving 
a lower step, incidentally lowering the center of gravity and making 
the car safer. It raises the rear end to give adequate rear springing. 

Q. What is the shape of the modern frame, in plan? 

A. It is gradually assuming a considerable taper. Originally, 
the frame formed a rectangle, with straight side members. Then it 
was found advantageous to narrow the front end to give more room 
for the front wheels to turn and thus allow a shorter turning radius. 
As this had the additional effect of shortening the engine-supporting 
arms, the makers were able to eliminate the sub-frame, with a saving 
of expense and weight. Finally, the width needed for modern 
touring car rear seats gradually widened out the rear ends of the 
frame, while the narrowing at the front became so great as to put a 
weak spot in the frame where its greater load had to be carried. It 


GASOLINE AUTOMOBILES 


565 


then became a logical step to make the frame taper from front to rear 
continuously, with straight sides. This is the form which all frames 
are assuming now. 

Q. In what other ways do modern frames differ? 

A. The rear cross-member is being eliminated very widely, as 
is also the front cross-member, so the triangular-shaped frame is not 
closed at either end. Formerly, the depth of the frame was pretty 
much the same from front to rear, but now this tapers very materially 
from the front up to the middle and then down again at the rear. A 
good stiff typical frame would be perhaps 2| inches to 3 inches deep 
at the front, 6 inches deep in the middle, and perhaps 2 \ inches to 2f 
inches deep at the rear. In short, except for perhaps 20 to 24 inches of 
length right in the middle, the frame depth would differ continuously. 

Q. What is the advantage of varying the depth so much? 

A. It eliminates every pound of excess weight, putting much 
metal where there is heavy load and severe stresses and little metal 
where the load and the stresses are light. 

Q. Is this form of construction more expensive? 

A. No. The art of pressing the frame out of sheet steel has been 
developed through large quantity production to such an extent that a 
frame of this type, with a constantly varying depth, costs no more than 
a straight frame cost four years ago. 

Q. Does this form give the repair man more to do? 

A. No. On the contrary, frames give less trouble in the way of 
sagging, breaking, or cracking than ever before. The frame troubles 
of today are mainly due to poor or light design, in an effort to lower 
weight too far, or to accidents. 

Q. What has been the effect of cantilever springs on frames? 

A. One effect of cantilever springs for rear use has been to 
eliminate the rear cross-member, as spoken of previously. Another 
effect has been to continue the deepest section back quite a few inches 
*■ to the point of support of the front end of the cantilever. 

Q. Is the trussed, or latticed, frame widely used? 

A. No. Only by one or two makers, although a few heavy^ars 
have a truss rod below the main frame to add stiffness and strength. 
The trussed, or latticed, frame is a new departure in frame design. 

Q. What are the noticeable tendencies in frame construction, 
other than those already mentioned? 


566 


GASOLINE AUTOMOBILES 


A. The use of heavier frames, that is, heavier sections of metal, 
deeper side members, and general stiffening is being accomplished 
without much gain in weight, owing to the better distribution of the 
metal. The combination of other units, as steps, step supports, and 
fenders with the frame is being worked out, this being one of the tend¬ 
encies in construction. The general carrying of spare tires at the 
rear is having an influence, but there seems quite a tendency to con¬ 
struct the body so as to enclose the tires, which, if carried out, would 
change this. 

Questions for Home Study 

1. How would you repair a sagged frame, if sagged at (a) front 
end; (b) center; (c) rear end; (d) cross-member? 

2. Describe the method of welding a cracked frame by the 
oxy-acetylene process. 

3. Describe the following frames in detail: (a) Stearns-Knight; 
(b) Marmon; (c) Fergus. 

4. How is the Franklin wood frame built up? 

5. How is what is called an “armored frame” made? 

6. Tell how to remove and replace an underpan. 

7. What material is usually used (a) for a truck frame; (b) for a 
light pleasure car; (c) for a heavy touring car? 

8. Give the advantages and disadvantages of pressed steel for 
frames. 

SPRINGS AND SHOCK ABSORBERS 

Q. What is the need for vehicle springs? 

A. To support the load in a flexible manner so that the jolts and 
jars of the road will not be transmitted to the passengers or load. In 
addition, a flexible connection between the power plant and the road 
wheels is needed. 

Q. How many recognized different types of spring are in use? 

A. Seven; all of which are made and used in all sizes and qual¬ 
ities for all kinds of load. 

Q. What are these seven types? 

A. The semi-elliptic, the full elliptic, the three-quarter elliptic, 
the platform, the cantilever, the quarter elliptic (or half semi-elliptic, 
as it is sometimes called), and the coil. All but the last three also are 
made with scroll ends, which alters the general appearance without 
altering the type of action. 


GASOLINE AUTOMOBILES 


567 


Q. What is the shape of the semi=elliptic? 

A. This form has a slight bow upwards, the two ends being 
slightly higher than the middle. The middle is attached to the axle 
and the ends to the frame, and when load is applied, these ends come 
down, flattening the spring so that it approaches a straight line. 

Q. Describe the full=elliptic spring. 

A. This form has the shape of two semi-elliptics, one inverted 
and set on top of the other. This gives it the appearance of an elon¬ 
gated letter O with points at the ends. The lower half is attached to 
the axle and the upper half to the frame, and loading tends to bring 
the two halves closer together, flattening the O still farther. 

Q. What is the form of the three=quarter elliptic spring? 

A. This consists of a flat lower semi-elliptic member and a 
highly curved quarter-elliptic upper member, the two being joined 
by means of a shackle. With the exception of the difference in 
curvature of the two parts and the use of the shackle to join them, 
this has the appearance of a full elliptic with the upper forward 
quarter cut away. When loaded, both members give slightly, the 
upper quarter more than the lower half. The shackle gives a consid¬ 
erable difference in this action from that of the full-elliptic. 

Q. What is the platform spring like? 

A. This spring consists of three semi-elliptics joined together at 
the ends so as to form three sides of a rectangle. The two sides are 
fastened, respectively, to the axle at the middle of each, to the frame 
at their front ends, and to the third spring at the rear ends. The rear 
spring is inverted and its center is fastened to the center of the rear 
end of the frame, while its ends are shackled to the rear ends of the two 
side springs. This makes a combination in which the normal semi- 
elliptic spring action is modified somewhat by the inversion of the rear 
cross-member and by the use of shackles at the ends of all three. 
While popular three or four years ago, it is now going out in favor of 
the three-quarter elliptic. 

Q. What is the cantilever spring like? 

A. It consists of an inverted semi-elliptic fixed or shackled to the 

% 

outside of the frame at the front end, hinged or pivoted slightly 
forward of its center to the outside of the frame, and having its rear 
end attached to the upper or lower surface of the rear axle. It is used 
in greater lengths than any other form of spring and is very popular. 


5G8 


GASOLINE AUTOMOBILES 


It is the most simple spring now in use and is said to give the easier 
riding of all. 

Q. What is the quarter=elliptic spring like? 

A. This is simply what its name indicates, one-half of a semi- 
elliptic or one-quarter of a full-elliptic. Its front end is fixed to the 
frame outside, and the rear end is shackled or allowed to slide on the 
rear axle. It is generally inverted. In reality, it is a cheap substi¬ 
tute for the cantilever or inverted semi-elliptic, this use being allow¬ 
able because of the light weight of both car and load. 

Q. Is this used in any different way? 

A. Sometimes a pair of these is used, one above the other, with 
the idea of doubling the resistance or rather of giving equal resilience 
with.but half the movement. 

Q. What is meant by underslinging? 

A. When this refers to frame, the entire frame is placed below 
the springs. This has gone out of use. When referring to springs, 
this means placing the spring below its support, as below the rear axle. 
This construction lowers the frame and center of gravity by the 
thickness of the spring plus its seat plus the diameter of the rear axle, 
sometimes amounting to a total of five inches. It is growing rapidly 
in popularity. 

Q. What is the purpose of a shock absorber? 

A. To absorb the small vibrations while the spring cares for the 
large ones. It generally takes the form of any auxiliary spring or 
friction device. 

Q. What are the general classes of shock absorber? 

A. Coil spring, flat-plate spring, friction plates, compressed air, 
and a few hydraulic (or liquid) forms. 

Questions for Home Study 

1. How are springs lubricated (a) as to leaves; (b) as to shackles? 

2. How are the spring leaves separated for lubrication? 

3. Describe a method of getting home with a broken rear spring. 

4. Why do racing cars have their springs wound with rope or 
cloth ? 

5. Describe the following car springs in detail: King; Winton; 
Ford. 

6. How do electric car springs differ from those of gasoline cars? 

7. What are the standard spring-plate widths? 


















GASOLINE AUTOMOBILES 

PART VI 

% 

FINAL-DRIVE GROUP 

REAR AXLES 

TRANSMISSION 

Units in the Final Drive. Generally speaking, the transmission 
is located in the middle or forward end of the chassis. When this is 
the case, the final drive begins right at the rear end of the transmission. 
The units back of the transmission, then, would be a universal joint; 
a driving shaft; possibly another universal joint; the final gear 
reduction; rear-axle shafts and enclosure; the differential; the torque 
rod, or tube, or substitute for it; the wheels; the brakes; the tires; 
and other smaller units. 

Even when the transmission is placed on the rear axle, this 
general layout is changed little, and the transmission, which has been 
covered in detail previously, is not considered again. In the case of a 
chain drive, which is still used on one pleasure car or perhaps two, on 
a number of small trucks, and on a large number of large trucks, this 
layout is changed considerably. In the large trucks, the transmission 
in perhaps 90 per cent of all cases would be in a unit with the jack- 
shaft, which means that for consideration in the final-drive group 
there would be only the driving shaft to the transmission; the joint 
or joints in it, if any; the chains and the method of adjusting them; 
the rear axle and wheels; the brakes; the differential, of necessity 
becoming a part of the transmission; and the jackshafts. 

To make this clear and point out the various units, it will be 
noted in Fig. 430 that it is a unit power plant. Directly back of the 
transmission is the first universal joint, driving through the hollow 
propeller shaft to the rear axle, in front of which is the second universal 
joint. The rear-axle group includes the axle shafts, differential gears, 
final gear reduction, gear housing, and the wheels. The torque 
reaction of the drive, to be explained later, is taken by the torque rod, 
marked in the drawing, which connects the rear axle to the under 



570 


GASOLINE AUTOMOBILES 



side of the stout 
frame cross-member 
in front of the axle. 

Universal Joints. 
The purpose of taking 
up the universal joints 
—it can be seen from 
the drawing—is to 
show how the rear 
axle rises and falls or 
moves sidewise in 
either direction with- 

e 

| out making any dif- 

f ^ ference in the trans- 

^ 'I mission of power to 

§J the axle. When joints 

1 4 are used at other 

a | points, the purpose is 

.■§ | generally to take care 
* 

^ | of any lack of align- 
•SI ment, but here the 
1 purpose is to transmit 
d | power at an angle. 

W fe. rnl 

^ ^ I he transmission 

^ | or power at an angle is 
J effected by construct¬ 
ing the joint so that it 
can work at any angle. 
Usually, this is done 
by constructing the 
central member in the 
shape of a cross, with 
four projecting arms 
or pins, all in the same 
plane. The ends of the 
two shafts are made in 
the form of forks, or 
Y’s, and are set at 









































































































































































































GASOLINE AUTOMOBILES 


571 


7'ight angles to each other, that is, the forks are laid in planes which 
are at right angles. The fork on one shaft is fastened to a pair of 
diametrically opposite pins, while the fork on the other shaft is fas¬ 
tened to the other pair of diametrically opposite pins. Each shaft is 
able to turn on its pins about a line through the center of both. As 
these two lines are in planes which are at right angles to one another, 
but intersect at a common center, movement is possible in either 
plane, or by combination movements of both, in any direction. 

Slip Joints. In many situations, a real universal joint is not 
needed, since the parts are not actually free to move in all directions; 
but what is needed is slight freedom up and down or sidewise 
combined with possible fore-and-aft movement. In such cases a slip 
is used, the name giving the idea of a joint which allows one shaft to 
slip, or slide, inside the other. The general construction of slip joints 
varies. Sometimes a round gear is fastened to the end of one shaft; 
this gear has a fairly large diameter and many teeth, with the teeth 
chamfered to an unusual extent—almost rounded, in fact. An internal 
gear of the same size and number of teeth with similarly rounded 
profiles is meshed with the hollow gear of the other shaft. Both 
gears have unusually wide faces. This combination gives an action that 
is almost universal, and also allows lateral sliding of perhaps \ inch. 

The second form of slip joint consists of a squared shaft and 
square enclosure. The end of the shaft has a member split along a 
central line attached to it; the exterior approximates a round of large 
diameter, but the interior is machined to a perfect square, one-half 
in each part of the split member. Attached to the end of the other 
shaft is a member machined to an exact square, but slightly rounded 
in a fore-and-aft direction. The square will drive, no matter in what 
part of the housing it is located, so that considerable fore-and-aft 
sliding is possible. In addition, the rounded surface of the square 
gives an approximate universal effect. The split housing is used to 
make assembling and disassembling easier and much quicker. Some¬ 
times such a housing is put on the end of each shaft, the connecting 
member being made in the form of a dumb bell, but with two square 
ends—one to work in each squared-out housing. In this way the 
effect of a full universal joint with the fore-and-aft sliding is obtained 
at less cost, and with easier assembling and disassembling as extra 
advantages, 


572 


GASOLINE AUTOMOBILES 


Occasionally a square joint is constructed as simple and small as 
possible, in which case the housing is not split and the shaft end is not 
rounded. This gives a simple square which drives through a simple 
squared-out hole. In this case there is no universal action, but simply 
lateral or sliding freedom. 

Other Flexible Joints. To get away from the complication of the 
universal joint and yet give practically the same results, many other 
forms have been produced. A very thin disc of tempered steel, with 
the two shafts bolted to the two opposite sides of it, has been used. 
The metal will bend and give enough to allow considerable angle of 

drive. Later forms of the same 
joint use leather in several 
thicknesses, the leather being 
bolted up to the two shafts in 
the same way. A joint of this 
kind, consisting of several lay¬ 
ers of fabric which have been 
fastened together in lamina¬ 
tions until a disc of fair thick¬ 
ness, say | to j inch, has been 
built up, is shown in Fig. 431. 
Then the leather is cut round 
and drilled for the bolts. In 
this form, six bolts is the pre¬ 
ferred number, three for each 
shaft end; they are in a three¬ 
armed spider fastened to the 
These newer forms are usually 
convenient for the repair man, for they allow breaking into the main 
shaft by the simple removal of the three bolts (or two as the case may 
be). By taking out the bolts at each end of such a shaft, the shaft 
itself can be removed, leaving the other units in the chassis ready for 
immediate removal, according to the needs of the repair job. 

Types. Possible types of final drive, from the gear box to the 
rear axle and the driving wheels or from the motor to the gear box— 
in case this is mounted on the rear axle, as is not uncommon practice— 
are practically limited, in cars of sound design, to shaft and double¬ 
chain constructions. 



Fig. 431. Laminated Discs Forming Flexible 
Shaft Coupling 

Courtesy of Thermoid Rubber Company, 
Trenton, New Jersey 

end of each shaft, as the figure shows. 




GASOLINE AUTOMOBILES 


573 


Shaft Drive. In its usual form, shaft driving in an automobile 
involves simply a propeller shaft interposed between the rear axle 
and a revolving shaft in the car above the spring action. There is 
some provision for taking the torque of the shaft and of the axle so 
that they shall maintain their proper relative positions. 

In Fig. 432, a typical short driving shaft with its two universal 
joints is shown. This is such a shaft as would be used in the car 
shown in hig. 430, except that the latter is a long wheel-base car with 
its transmission in a unit with the motor and clutch and thus, far 
forward. This combination necessitates a very long propeller shaft. 
The one shown is actually from a car having a short wheel base, with 
the transmission located amidships. This is a combination which 
calls for a fairly short propeller shaft. 

The short shaft, shown in the figure, is a solid shaft. The modern 
tendency toward lighter weights is being worked out in the case of 



Fig. 432. Ordinary Driving Shaft of Solid Form with Two Universal Joints 

$ 

propeller shafts, and many are now made hollow. By making the 
diameter slightly larger and having a large central hole, unusually 
light weight is obtained with all the strength of the solid form. In 
addition, the larger diameter hollow shaft has more rigidity than the 
small diameter solid form, and in many of the modern cars without 
torque or radius rods, unusual rigidity of the driving shaft is necessary. 
Other forms have been used for the driving shaft, but they come more 
or less in the freak class. About two years ago, a car was brought out 
with a spring, or flexible, shaft, which consisted of a rectangular 
member of considerable height, but fairly thin. The idea was not only 
to transmit the power of the engine, but to do it in a flexible manner, 
that is, the shaft was supposed to absorb all the sudden changes, 
such as quick acceleration or quick braking. At the same time, one of 
the electric-car makers brought out a chassis with a square driving 
shaft of very small size. This served the same purpose as. the flexible 





574 


GASOLINE AUTOMOBILES 



shaft only in a different way; its two ends, setting in square holes, 
formed two sliding joints without further machining. 


Fig. 433. Ford Final Drive, Differential, and Axles 



Fig. 434. Worm and Gear for Rear Axle, Showing Upper Position of W'orm 
Courtesy of Timken-Detroit Axle Cojnpany, Detroit, Michigan 

An objection to the shaft type of drive is that the reaction of the 
revolving shaft tends to tilt the whole car on its springs in a diree- 






GASOLINE AUTOMOBILES 


mr 

bib 



tion opposite to that in which the shaft is turning. In some cars, 
this is counteracted by the use of slightly heavier springs on one 
side. The advantages of the shaft drive are the complete enclosure 
of all working elements, with their consequent protection from dirt 
and the assurance of their proper lubrication. 

The final drive of the Ford automobile, in which the end of the 
propeller shaft is shown at .1, together with the bearings in which it 
revolves, the pinion by which it drives the car, the axle, the differen¬ 
tial, and the bearings of 
the floating inner ele¬ 
ments of the axle is illus¬ 
trated in Fig. 433. 

The shaft drive does 
not necessarily include 
the use of bevel gears for 
the final reduction at the 
rear axle; in fact, almost 
any form of gears may 
be used. In one well- 
known shaft-driven com¬ 
mercial car, the final 
gears consist of a pair 
of plain spur gears, while 
on the shaft of the second 
of these gears is a pair of 
bevels. 

As soon as the bevel 
gear final reduction dis¬ 
closed its limitations and 


Fig. 435. Spiral Bevel Gears—a New Noiseless Type 
for Rear Axles 

Courtesy of Timlcen-Detroit Axle Company, 
Detroit, Michigan 


disadvantages, designers started to displace it. One of the earliest 
forms of gear used for this purpose was the worm, an example of which 
can be seen in Fig. 434. This figure shows the worm placed above the 
wheel, but the lower position, which is also used, has the advantage of 
copious lubrication. In the form shown, the wheel must come directly 
beneath the worm so that the differential may be set inside of it. 

The worm is usually more suitable for slower moving vehicles 
which have a large reduction of speed between engine and rear wheels, 
that is to say, it is peculiarly fitted to electrics and motor trucks of all 








576 


GASOLINE AUTOMOBILES 


sizes, on which it is finding wider and wider use. On pleasure cars 
of the average size and type where a speed as high as 50 m.p.h. or 
higher is expected by all concerned, it has not been found suitable and 
consequently is not being used. 

A later form, which is designed to replace the straight bevel, is 
the spiral bevel. This is primarily a bevel gear with spiral teeth, the 



Fig. 436. Typical Roller Chain 


idea being to incorporate in the bevel gear the advantages of the 
spirally shaped worm tooth, without its disadvantages. As Fig. 435 
shows, this makes a very compact and neat arrangement, the differ¬ 
ential fitting within the larger gear in the same manner as with the 
worm. 

Double-Chain Drive. The use of double chains, by which the 
driving wheels of an automobile are driven from a countershaft 
across the frame of the machine, is a practice possessing a number 
of advantages. But because of the noise and quick wear with badly 



Fig. 437. Typical Silent Chain 


designed chain drives and the difficulties of completely enclosing the 
driving mechanism, chains are not now as popular as formerly. 
Nevertheless, the elimination of universal joints working through 
large angles and under heavy loads, the avoidance of heavy weights 
carried on rear axles without spring support, the lowering of the 
clearance by the differential housings, etc., are very real objections 
that the double chain avoids. 

For trucking and other heavy service, chains are still commonly 
in use, and it is the belief of many that a better understanding of their 





























































GASOLINE AUTOMOBILES 


577 


merits and the means of securing these merits in positive and per¬ 
manent form will result in their more general use. 

A typical roller chain of the type most used for automobile 
drives is illustrated in Fig. 436. 

- Silent chains, of the types illustrated in Figs. 437 and 438, possess 
certain points of superiority over roller chains and are therefore com¬ 
ing increasingly into use for camshaft drives, in gear boxes, etc., and 
there is some possibility that they will find more extensive application 
to final drives than at present. 

The action of a silent chain is illustrated in Fig. 438, in which it 
is seen that as the chain links enter the sprocket teeth the chain 
teeth at the same time close together and settle in the sprocket with 


Fig. 438. Action of Silent Chain and Sprockets 

a wedging action that causes them to be absolutely tight, but without 
any more binding than there is backlash. 

To keep silent chains from coming off sidewise from the sprockets 
over which they run, it is customary to make the side links of deeper 
section than the center links, as is illustrated in Fig. 437. Another 
successful scheme is grooving the sprocket to receive a row of special 
center links in the chain, which are made deeper than the standard 
links. 

At present, only one American pleasure car, the Metz, has 
final drive by means of silent chains. This is a small car with a 
friction transmission, the drive from the ends of the cross-shaft being 
by enclosed silent chain to each rear wheel. 

Torque Bar and Its Function. It is a well-known fact that action 
and reaction are equal and opposite in direction, so that if a gear is 
turned forcibly in one direction, say clockwise, there is a reaction in 
the opposite direction, or counter-clockwise. This is the simple basic 
reason for a torque bar, or torque rod, on an automobile. It is needed 
with any form of final drive, but it takes different forms, according to 





578 


GASOLINE AUTOMOBILES 


the type of gear used. The bevel and spiral bevel used on 88 per cent 
of the 1917 cars are explained in detail as follows: Fig. 439 shows the 
rear end of a typical pleasure-car chassis. The engine is rotating 
clockwise, and so is the driving shaft A, as shown by the arrow. The 
shaft turns the pinion B in a clockwise direction, which rotates 
the large bevel C so that its top turns toward the front of the car. 
The bevel C turns the rear axle 1) and the rear wheels (not shown) 
in the same direction; so the car moves forward. 

In addition to the gear C and shaft D turning easily in the axle 
housing E, there is an equal and opposite reaction which tends to keep 
them stationary, while the bevel pinion B and driving shaft A tend 
to rotate around the rear axle as a center in a counter-clockwise direc- 



Fig. 439. Diagram to Show What Torque Is and Why Torque Rods are Necessary 


tion, as shown by the diagram. If the rear axle were held firmly 
so it could not rotate, and there was nothing to restrain the bevel 
pinion and shaft, this could easily happen. However, since we do 
not wish this to happen, a means is provided to oppose this action 
and prevent it from happening. Since the turning force which makes 
the shaft rotate is called the torque, this rod, bar, or tube, whatever 
its form, is called the torque member. 

In the sketch, the torque member is marked F and is attached to 
the frame .cross-member G, between a pair of springs, so as to cushion 
the shocks of sudden car or shaft movements. The force on this is 
the force which tends to rotate the driving shaft and pinion counter¬ 
clockwise, so that it works upward, as shown by the arrow. The 
frame prevents this and absorbs the force. 







GASOLINE AUTOMOBILES 


579 



Fig. 440. 


Diagram to Explain Driving Reactions 
Using Radius Rods 


Driving Reaction. As has been stated, the power, or torque, of 
the motor is used to rotate the rear wheels. These stick to the pave¬ 
ment or road surface, so 
the car is really pushed 
forward. Since it is this 
pushing action which 
really moves the car for¬ 
ward, it is very interest¬ 
ing to note how this push 
is transmitted from the 
wheels and rear axle to 
which they are attached 
to the frame which car¬ 
ries the body and pas¬ 
senger load. 

The transmission of 
the drive to the body is 
accomplished in one of 
three ways. The first form was the so-called radius, or distance, 
rod, which the shaft-driven car inherited from the chain-driven form. 
In the chain drive, these 
rods were a necessity and 
served a double purpose; 
they kept the driving and 
driven sprockets the 
proper “distance” apart 
for correct chain driving 
(hence their name “dis¬ 
tance” rods), and they 
also transmitted the drive 
back to the frame. On 
the shaft-driven car, the 
distance function is not 
needed, so they are called 
radius rods. x4s shown 
in Fig. 440, they transmit 
the drive forward to the frame, thus propelling the car in the direc¬ 
tion of the arrow, and they also keep the rear axle in its correct position. 



Fig. 441. 


Layout of Driving Reaction Using Torque 
Tube around Shaft 



















580 


GASOLINE AUTOMOBILES 


In lightening and simplifying the shaft-driven car, designers 
figured that three members for the torque and driving reactions were 
too many; so a design was worked out in which all three were combined 
into one, which is a form of tube surrounding the shaft, l his made 
the member light but strong, and simplified the whole rear end. As 
shown in Fig. 441, the tube has forked ends at the front, which are 
connected to the frame cross-member in such a way as to absorb the 
torque reaction and also to transmit the drive. 4 he method has 
the further advantage of needing but one universal joint, and that 
at the front end. Furthermore, it gives a correct radius of rise and 
fall for the rear axle, since the center of the combined torque and drive 

member is also the center of 
the universal joint in the 
driving shaft. In the form 
shown in Fig. 339 (radius 
rods not shown), the two 
different centers will be 
noted, the torque rod giv¬ 
ing a greater radius than 
the shaft. Similarly, in 
Fig. 440 (where the torque 
rod is omitted for clear¬ 
ness), the rods give a 
longer radius of rear-axle 
movement than the shaft, 
which has a joint close to 
the axle. 

It will be noted that both these methods allow complete freedom 
of the rear springs, which may be of any form, and shackled at the 
front end if desired by the designer. In its newest and simplest form, 
the so-called Hotchkiss, or spring, drive has both the radius and 
torque rods omitted, the springs being forced to transmit both forces, 
as shown in Fig 442. In this case, the forward end of the rear spring 
must act as a rod, or lever, instead of as a spring, and must be fairly 
straight and stiff without a shackle, but firmly pivoted on the frame. 
In addition, the shaft must have two universal joints, as shown. 

It must be stated, as a simple fact, that this last form is increas¬ 
ing rapidly and at the expense of the other two. On smaller lighter 



M 


Fig. 442. Arrangement of Driving Reaction When 
Hotchkiss Drive is Used 





GASOLINE AUTOMOBILES 


581 


cars it is gradually replacing all other forms. It has the advantages 
of minimum weight and fewer parts, and applies the driving force in a 
direct line to the frame, the same as the two radius rods do. On the 
other hand, it makes the springs serve a triple purpose, the demands 
on these for torque and drive transmission and absorption being such 
that the spring flexibility must be negligible, which makes the car ride 
hard. In addition, making the springs handle the three widely 
different actions puts additional stresses upon them, so that they are 
more likely to break. On the medium size and larger heavier cars, 
this construction is not gaining so rapidly. 

TYPES OF REAR AXLES 

Classification. Rear axles may be divided into the following 
classes, distinguished according to the method of carrying the load and 
taking the drive: the form in which the axle carries both load 
and drive; the semi-floating form, carrying the drive and a small part 
of the load, the axle shafts not being removable without removing 
the wheels; three-quarter floating form, carrying the drive and a small 
part of the load, the latter being divided between the shaft and its 
housing, but with the shafts removable; seven-eighths floating form, 
carrying the drive but not the load, the arrangement of bearings to 
take the load being such that the wheel hubs do not rest wholly and 
solely upon the axle-casing end; the full floating form, in which the 
shaft does nothing but drive, and is removable at will without dis¬ 
turbing the wheel and wheel weight resting on the axle-casing end, 
which is prolonged for this purpose. 

The seven-eighths floating type has been developed to meet the 
need which arose for a floating construction, in which the axle casing 
did not pass entirely through the wheel hubs. With the full floating 
form, any accident to the wheel, in which it was struck from the side, 
also damaged the casing, or tube, end. The result of this in nine 
cases out of ten was to make the removal of the wheel impossible, 
because the tube end, which projected through, was bent over. 
Moreover, repairing in such a situation called for a new axle casing 
—a very expensive proposition. Consequently, the seven-eighths 
floating form was developed to present all the advantages of the 
full floating form, with this serious drawback eliminated by a rear¬ 
rangement of the parts which did not necessitate prolonging the axle 


582 


GASOLINE AUTOMOBILES 



^ 7 oaffsrf 



/s/Vl 


through the wheel hubs. Despite the facts, it did not gain as rapidly 
as the other floating forms, and now is almost out of use. 

The three diagrams in Fig. 443 explain the types as well as words 
can. At the top is shown the full floating axle, the best but most expen¬ 
sive form. In the middle, the semi-floating axle, which makes the axle 
shaft do all the work—carrying load as well as transmitting power—is 

shown. At the bottom is the 
three-quarter floating form, 
which is really a combination 
of the other two forms and 
possesses a maximum of ad¬ 
vantages with a minimum 
cost. The car weight is car¬ 
ried on the tubing, while the 
shaft drives and carries a por¬ 
tion of the side stresses to 
which the wheels are sub¬ 
jected, the quantity depend¬ 
ing upon the construction of 
the bearings. 

Of the 1917 cars, prac¬ 
tically 30 per cent (29.5) have 
the three-quarter floating rear 
axle, 25.5 per cent the semi¬ 
floating form, and 43.5 per cent 
the full floating form. In 1916, 
however, the three-quarter 
form was used in but 22.8 per 

Fig. 443. Arrangement of Axle Bearings and Hous- tent, and 111 191 O 111 Only 18.0 
ing in Three Principal Forms of Rear Axle ^ ^ of ^ carg These 



aS errrr -fHfocrf/rrj 



Vv 


figures show how the three-quarter floating axle has been gaining 
constantly at the expense mostly of the floating form, the semi-floating 
form practically standing still for three years. 

Axle Carrying Load and Drive. The type in which the axle 
carried both load and drive was a peculiar one and did not last long. 
In this form, the rear-axle shafts were exposed and carried the 
weight of the load at the spring seats, which were bushed to allow 
the shafts to turn within them. This made a place which was hard 


i 




































































































Fig. 444. Rear Construction Embodying Dropped Type of Rear Axle 

which the weight of the car as well as the weight of the load is carried 
on the I-section drop-forged rear axle, while the drive is transmitted 
from the transmission by the usual shafts, which carry no load. The 
cut shows the complete assembly above and the dropped axle below. 
The round ends of the I-beam axle are hollow, carrying the driving 
shaft through the central hole and the wheels on bearings which 
fit over the outside. The wheels will revolve on the bearings, even 
if the inner shafts and transmission be removed from the chassis. 

Despite its manifold advantages, the expense of constructing 
an axle of this type—it is practically the same as that of two ordi- 


GASOLINE AUTOMOBILES 583 


to lubricate, and yet which was down in the dust and dirt, so that 
lubrication was a great necessity. All these causes, coupled with the 
fact that the axle carried both load and drive, caused its disuse. 

Dropped Rear Axle of Full Floating Type. The dropped type 
of axle is not much used at present for cars of the shaft-driven type, 
the dropped part of the axle bed being used to hold the rearward- 
placed transmission, tig. 444 shows a former American type, in 







584 


GASOLINE AUTOMOBILES 


nary axles, making the total cost double that of any other form has 
worked to prevent its general use. In fact, it is not now in use in 
this country, as the maker has gone out of business. 

A prominent French constructor, De Dion, utilizes a dropped 
rear axle, but, in this, the differential casing and gearing are suspended 
from the frame and drive down to the axle shaft by means of a pair 
of short inclined shafts with two universal joints in each, that is, 
the drive from the differential to the two wheels contains four universal 
joints. The inevitable loss due to the necessarily short inclined shafts 
and to the two joints in each has deterred other manufacturers from 



using this form, although a few makers—notably the Peerless Com¬ 
pany—have inserted a pair of joints in the rear axle in order to give the 

rear wheels the same camber as the front wheels. As this necessitates 

/ 

inclined shafts, the joints are needed to connect the horizontal center 
part with the inclined ends. 

Clutch Forms in Semi=,Three=Quarter, and Full Floating Types. 

The main point of difference in the various semi-, three-quarter, and 
full floating axles, aside from the principle of design which makes them 
decidedly different, is the clutch, by means of which the wheel is driven. 
In some cases, this clutch takes the form of a gear, with straight sides 


































































































GASOLINE AUTOMOBILES 


585 


and external notches, or jaws, to correspond with the teeth, but 
usually it is more of a claw type, the driving ends projecting inward 
from the point of attachment to the axle shaft. Another notable 
point of difference and one which makes a huge difference in the cost 
-lies in the machining of these jaws, whether they are attached to the 
axle or machined up with it in one piece. The latter is considered 
better and stronger in every way, but, as it is much more expensive, 
it is used only on the best cars. 

The driving clutch takes various forms, one of which is shown 
in the Studebaker axle, Fig. 445. In this type, the axle is a square 
rod acting within a square hole in the hubs. In the small detail at 
the upper left-hand corner the letter A shows the square upon which 
the driving clutch is slipped. The spaces at the inner ends of this 
indicate the clutches, or jaws, which mesh with corresponding slots 
on the wheel hub and thus do the driving. 



Fig. 446. Rear Axle, Showing Wheels Driven by Spur Gears 

The dropped type of axles are neither all shaft-driven nor all 
chain driven. Fig. 446 shows one that is of the spur-gear driven 
type. The dropped axle bed C is of tubular form, and the differ¬ 
ential case is dropped down on and slightly back of the rear axle, as 
at B. From this case, two shafts A A extend out to the sides, driv¬ 
ing the wheels through the medium of the spur gear D, which meshes 
with internal gears within the wheel hubs (not shown). This type of 
rear axle and drive is used on a number of the Fifth Avenue stages 
in New York City. 

InternaLGear Drive for Trucks. The spur-gear driven type 
just described is gaining rapidly for motor-truck use, because it has a 
number of important advantages. Besides carrying the heavy load 
on a member able to withstand any amount of overload, it materially 
lightens the power-transmitting portion of the axle, which is enclosed 
and therefore quiet. It is simple and inexpensive to construct and 
repair. Fig. 447 shows a section through one of these axles, which is 





GASOLINE AUTOMOBILES 


580 


used on a very light truck of f-ton capacity. In this figure, it will be 
noted that the load-carrying axle is behind the power-transmitting 

shafts, consequently the for¬ 
mer is straight. In Fig. 446, 
the load carrying axle is in 
front and consequently must 
be bent down at the center. 
This bend is a source of weak¬ 
ness. 

Full Floating Axle. Fig. 
448 shows a full floating axle, 
with the ends of the driving 
shafts projecting beyond the 
housing and carrying five 
jaws which mesh with 
five similar ones in the wheel 
hubs and thus drive the 
wheels. Unless the jaw end is 
welded on to the shaft, this 
makes a very expensive axle 
despite its many good points. 
Fig. 449 shows the rear con¬ 
struction of a car with full 
floating axle, with the brace 
below it for the purpose of 
strengthening the whole con¬ 
struction. The large diam¬ 
eter brake drums, shown close 
to the wheels, are made of 
pressed steel and are united 
to the axle tubing, which is 
also united to the differential 
housing, so that the whole 
forms one large and continu¬ 
ous piece, except where the 
differential unit bolts on one 
side and the cover on the 

Courtesy of Russell Motor Axle Company , . x T 

Detroit, Michigan other. JNote that the shaft 


























































































































GASOLINE AUTOMOBILES 


587 





Fig. 449. Timken Full Floating Rear Axle, Showing Differential Removed 
Courtesy of Timken-Detroit Axle Company, Detroit, Michigan 


has the driving clutches machined as an integral part, and that 
removing the two shafts for a few inches makes it possible to unbolt 


Fig. 448. Example of Full Floating Type of Axle 


Fig. 450. Timken Full Floating Rear Axle with Spiral Bevel Gears 

and remove the entire differential unit. For the sake of compari¬ 
son, Fig. 450 shows an axle which differs from Fig. 449 only in having 
spiral bevels substituted for the ordinary straight-tooth bevels. In 


A 





















588 


GASOLINE AUTOMOBILES 


Fig. 450, the differential unit is removable in Lie same manner as 
in Fig. 449. One of the axle shafts, with its integral driving clutches, 
and the differential cover are shown below. Note the two plugs in 
the cover; the upper one is for filling the case with lubricant, while the 
lower plug acts as a level indicator. When it is opened, heavy oil 
or Oil and grease combinations are put in the filling plug above until 
the lubricant begins to flow out of the lower opening. 

Three=Quarter Floating Axle. An interesting study in rear axle 
design is.seen in Fig. 451. This axle has a number of points in which 



Fig. 451. Partial Section through Rear Axle of Case Car, Showing Construction 
Courtesy of J. I. Case T. M. Company, Racine, Wisconsin 


it differs from previously described forms. It is of the three-quarter 
floating type. Note the enclosure of the driving shaft and the splines 
at its forward end for the universal joint, also the housing for the joint 
forming the torque member. The small roller bearing for the spigot 
end of the driving shaft beyond the bevel pinion is unusual; so are 
the diagonal distance rods, the spherical seat for the springs, the 
combination of drawn-steel tubes, steel castings, and pressed-steel 
cover for the axle housing. The wire wheel and its method of attach¬ 
ment will be seen, also the double set of brakes, internal and external 





























































































































GASOLINE AUTOMOBILES 


589 


on the same drum, with operating shafts for both supported from the 
centra] part and ends of the axle housing. 

Rear=Axle Housings. Rear-axle housings are usually of pressed 
steel, although castings play a very important part and are some¬ 
times used alone and sometimes in combination with other castings or 
in combination with pressed steel. Aluminum, although not a depend¬ 
able metal, is used quite a good deal for the purpose of saving weight, 
as excess weight upon the rear axle is anything but desirable. In 
one unusual but effective combination, the axle housing consists 
of two malleable-iron castings joined together by means of bolts at 
the centers, the brake drums being cast as a part of the tubes. While 
not usual, this is safe practice, for malleable iron is tough and will 
not break or splinter. It seldom is the case, however, that the axle 
casing is reduced to as few parts as are shown here. 

Welding Resorted To. Where the differential housing or brake 
drums are of malleable iron, cast steel, or even of pressed steel, and it 
is desired to unite them with the steel tubing forming the main part 
of the shaft housing, welding is now universally used. Formerly, 
it was good practice to make the casing a drive fit on the tube, riveting 
it in place, or else soldering it in place, making doubly sure by using 
rivets. Now, however, welding is resorted to, either the oxy- 
acetylene, electric, or some other process being used. 

In the axles shown in Figs. 449 and 450, it will be noted that 
the axle shell is of pressed steel, to which the spring seats are bolted, 
the remainder of the construction being formed by drawing. In Fig. 
448, however, the construction is such as to necessitate making the 
two halves longitudinally and then bolting or spot-welding them 
together. Being machined after they are fastened together, it makes 
as accurate a construction as the one-piece jobs, Figs. 449 and 450. 

Effect of Differentials on Rear Axles. A differential gear, 
sometimes called a balance, or compensating, gear, is a mechanism 
which allows one wheel to travel faster than the other and which 
at the same time gives a positive drive from the engine. This device 
is a necessity in order to allow the car to go around a curve properly, 
for in doing so the outer wheel must travel a greater distance than 
the inner one during the same interval of time. 

There are two forms of differential, the bevel type and the all-spin 
type, the latter differing from the former only in the use of spur gears 


590 


GASOLINE AUTOMOBILES 


m 


instead of bevel gears. The principle used in both is that a set of 
gears are so held together that when a resistance comes upon one 
part of the train of gears the whole train will stop revolving around 
on a stationary axis and revolve around another gear as an axis, the 
first gear, in the meantime, standing stationary, or practically so, 
according to the amount of the resistance encountered. In the 
bevel type, a pair of bevels are set horizontally. Between the bevels 
is a spider with three or four arms, with a small bevel on the end of 
each. These small bevels mesh with the larger bevels at the sides 

and ordinarily stand still, ro¬ 
tating around on the arm of 
the spider as an axis by virtue 
of the continued rotation of 
the two side gears in opposite 
directions. When one wheel 
meets greater obstructions on 
the road than the other, thus 
holding it back, the shaft 
which drives that wheel lags 
behind the shaft driving the 
other wheel and thus holds 
back the horizontal gear at¬ 
tached to the shaft. This 
retarding movement allows 
the other horizontal gear 
more freedom to rotate. The 
result is that the spider carry¬ 
ing the smaller bevels rotates 
around on its axis, thus imparting to the free gear attached to the free 
wheel an additional motion, and to the free wheel a doubled speed, 
while the retarded wheel has a lessened speed. This takes the car 
around the corner without breaking the rear axle, as would be the 
case without some such contrivance. The description of the bevel 
differential action applies equally well to the spur type, except that 
all gears are spurs. 

The dividing of the rear axle is, of course, done to make a place 
for the differential gear to work, and much time and thought have been 
given to this subject in an endeavor to work out a substitute which 



Fig. 452. Peculiar Differential Construction 

























































































GASOLINE AUTOMOBILES 


591 


would permit the differential action and still allow the strengthening 
of the rear axle. Fig. 452 shows one solution of the problem, which 
has been worked out in such a way that the differential is moved 
forward into the driving shaft. The rear axle shafts are thus greatly 
strengthened, the designer being unhampered by the presence of the 
differential in the rear axle. In this design, one side gear of the bevel- 
gear differential is carried upon a shaft, and the other upon a tube 
around the shaft. Then, at the rear axle, two sets of bevel gears 
B 2 B 3 and AiA 2 are used, Ai being driven by the main shaft, and driv¬ 
ing the right-hand shaft through the gear A 2 ; while the other B 2 is 
driven by the tube, and drives the left-hand shaft through the gear B 3 . 
In this case the axle shafts are made much larger than in the ordinary 
case, while the differential action is just the same. 

Improved Forms of Differential. Lately, much work has been 
done upon differentials to cause them to act as differentials should. 
The present form of differential acts according to the amount of 
resistance offered, but should act according to the distance traveled. 
When no resistance is offered, all the power is transmitted to that 
wheel, leaving the other stationary. This is just the opposite of the 
desired effect. If a differential were constructed to work for distance 
only, then, in the case of a wheel on ice or other slippery surface which 
offered little or no resistance, both wheels would still be driven 
equally, and the power transmitted to the one not on the ice would 
pull the vehicle over it. 

One way in which the differential action might be corrected is 
by the use of helical gears and pinions instead of the usual bevel or 
spur gears. In the M & S forms, this construction is used, Fig. 453, 
showing the form constructed by Brown-Lipe-Chapin. In this form, 
each axle shaft carries a helical gear, and the differential spider carries 
two.helical pinions with radial axes and four additional pinions, each 
of which meshes with one of the radial pinions and one of the gears 
on the axle shafts. On a turn, the outer wheel tends to run ahead 
of the inner and thus causes the nest of helical gears to revolve. All 
gears and pinions have a right-hand 45-degree tooth, so that one wheel 
may revolve the housing if the other is locked or held, but it is impos¬ 
sible to turn the free road wheel by pulling on the housing. The 
principle is the same as a worm steering gear in which the turning of 
the hand wheel may be transmitted to the front wheels, but the gear 


592 


GASOLINE AUTOMOBILES 


cannot be operated from the wheel end, because the worm is irrevers¬ 
ible. This differential is used to advantage to prevent spinning on 
slippery ground and also to eliminate the skidding which the ordinary 
differential gives. 

Another somewhat similar device has but two pairs of helical 
pinions in addition to the two helical gears on the shafts, the axes of 
each pair being set at an angle to the others. Thus, each helical 
gear and its pinion form an irreversible gear combination, so that 
movement cannot be transmitted through either in the reverse direc¬ 
tion. This form fulfills the same conditions as the Brown-Lipe- 
Chapin M & S form, as the construction is such that no motion can be 




Fig. 453. The M & S Helical Gear Differential in Sections 
Courtesy of Brown-Lipe-Chapin Company, Syracuse, New York 

transmitted from the differential spider or housing to one of the wheels 
alone. 

The above principle is back of the gearless form, shown in Fig. 
454, in which the result is achieved through ratchets instead of heli¬ 
cal gears, the lack of gears giving it its name. In this form there are 
two ratchets Y and Yl, which are keyed to the two axle shafts and 
free to rotate independent of the housing. The round members 
marked B are the interlocking pawls; the upper one is in a tooth of the 
right-hand ratchet at the right and is driven by the contact face of 
the driving sector X at the left. Thus, the right-hand ratchet is 
being driven positively forward. The lower pawl is engaged at 
the other end; so the left-hand ratchet is also being driven positively 






























































GASOLINE AUTOMOBILES 


593 


forward. On a turn, one wheel revolves faster than the other, say 
the right, and causes the right-hand ratchet to move faster than the 
differential housing, which can only go as fast as the other, or slow- 
moving, wheel. Then, the right-hand ratchet pushes the end of 
its pawl out of the tooth and gives it a free movement forward. As 
soon as the wheels revolve at equal speeds, the spring pushes it back. 
In the figure, the right-hand portion shows the original form in 
perspective. 

Possible Elimination of Differential. The whole modern tend¬ 
ency is toward differential elimination. In the cyclecars and small 
cars brought out in recent years, designers have been forced to get 



Fig. 454. Sketches Showing Construction and Operation of Gearless Differential 


along without it because of the demand for simplicity, light weight, 
and low price. This effect has been obtained by the use of a pair of 
driving belts, letting one slip more than the other; by the use of fric¬ 
tion transmissions; by simply dividing the rear axle and letting one 
side lag when there was resistance; by not dividing it and letting 
one wheel drag; and in other ways. The evident success of these 
small vehicles without a differential or any real substitute for one 
has set designers to thinking about this subject again, and some 
big cars without a differential, or with a more simple and less 
expensive substitute for it, may appear in the near future. 

Rear=Wheel Bearings. The bearings used on rear axles differ 
very little from those used on front axles. All forms are used—plain 

c/ A 



























































594 


GASOLINE AUTOMOBILES 


bearings, ball bearings, ball thrusts, roller bearings in both cylindrical 
and tapered types, and all combinations of these. Thus, Figs. 445 
and 452 show the exclusive and liberal use of ball bearings, while Fig. 
451 shows all rollers of two kinds and ball bearings for thrust bear¬ 
ings only. The two kinds of roller bearings are the tapered roller and 
the flexible roller. Similarly, in Fig. 447, it will be noted that balls 
are used with two kinds of rollers, straight solid rollers in the wheels 
and flexible rollers in the differential case. Figs. 449 and 450 show 
the exclusive use of the tapered roller type, a construction which is 
gaining ground very rapidly, the same as in front axles, although, 
formerly, ball bearings were most widely used. The materials 
employed are similar to those used for front axles, which have been 
previously described. Cases are made of all kinds of steel and iron— 
pressed, drawn, cast, etc.—not to speak of crucible steel, malleable 
iron, manganese bronze, phosphor bronze, aluminum, aluminum 
alloys, and many combinations of these materials in twos and threes. 

Rear=Axle Lubrication. Rear-axle lubrication is generally 
automatic in so far as the central bevel or other gears and the differ¬ 
ential housing are concerned. The housing usually has a form of 
filling plug, or standpipe, which is used to fill the case with a form 
of heavy grease every 5000 miles, or once each season. The case is 
generally arranged so the filling plug works through and lubricates the 
outer bearings on the axle shafts as well, with suitable provision 
against this reaching the brake drums or other brake parts. The 
wheel bearings either are cared for in this way or have a central 
space which is filled with heavy grease once a season, being self- 
lubricating from then on. Such other rear axle parts as need occa¬ 
sional lubrication, as torque-rod pivots, brake-band supports, brake- 
operating shafts, etc., are generally provided with external grease cups, 
which are given a turn once a week on the average. It is highly 
important that the braking system be as well lubricated as the lubri¬ 
cating means provided will allow. 

REAR=AXLE TROUBLES AND REPAIRS 

Jacking=Up Troubles. Much rear-axle work—practically all, 
in fact—calls for the use of the jack. True, the full floating type of 
axle can have its shaft removed without jacking, but, aside from 
differential removal, there is little rear-axle trouble in which it is 


GASOLINE AUTOMOBILES 


595 


necessary to remove the shaft alone. In almost all cases, the axle 
must be jacked up. Many axles have ii truss rod under the center, 
and this is in the way when jacking; however, this can be overcome. 
Make from heavy bar iron a U-shaped piece like that shown on 
top of the jack in Fig. 455, making the width of the slot just enough 
to admit the truss rod. The height, too, should be as little as will 
give contact with the under side of the axle housing. 

Substitute for Jack. A good substitute for a jack is a form of 
hoist, Fig. 456, which will pick up the whole rear end of the car at 
once. This not only saves time and work, but holds the car level, 
while jacking one wheel does not. Moreover, with a rig of this kind, 
the car can be easily lifted so high that work underneath it may be 
easily done. The usual hoisting blocks are very expensive, but the 
above hoist can be easily made by the ingenious repair man. This 
one was made from an old whiffletree with a chain attached at each 
end. For the lower ends of the chains, a pair of hooks are made 
sufficiently large to hook under and around the biggest frame to be 
handled. With the center of the whiffletree fastened to the hook of 
a block and tackle, the hoist is complete. By slinging the hooks 
under the side members of the frame at the rear, it is an easy matter 
to quickly lift that end of the chassis any distance desired. 

Workstand Equipment. Next to raising the rear axle, the most 
important thing is to support it in its elevated position. To leave it 
on jacks is not satisfactory, for they will not raise the frame high 
enough, and, furthermore, they are shaky and may easily let the whole 
rear end fall over, doing considerable damage. With the overhead 
hoist, the chains or ropes are in the way; so a stand is both a necessity 
and a convenience. In Fig. 457, several types of stands are shown. A 
is essentially a workstand, intended to hold the axle and part of the pro¬ 
peller shaft while repair work is being done thereon. It consists of 
a floor unit, or base, built in the form of an A, with six uprights let 
into it, preferably mortised and tenoned for greater strength and 
stiffness. Then, the four rear uprights are joined together for addi¬ 
tional stiffness and rigidity. If casters are added on the ends, the 
stand can be more conveniently handled around the shop. 

The forms B are for more temporary work and consequently 
need not be so well or so elaborately made. The little stand C is a 
very handy type for all-around work. Stands of this kind with the 


59G 


GASOLINE AUTOMOBILES 


top surface grooved for the axle are excellent to place under cars 
which have been put in storage for the winter. 

The stand D is, like A, a workstand pure and simple. In this, 
however, the dropped-end members allow supporting the axle at 




those points, while the elimination of central supports gives plenty 
of room for truss rods. This type of stand would preferably be made 
from metal, pressed steel or small angle irons being very good. Every 



Fig. 457. Types of Handy Stands for Rear-Axle Repair Work 


repair shop should have a considerable number and variety of stands, 
made as the work demands them, to fit this particular class of work. 

UniversaLJoint Housings. LTniversal joints usually are covered 
with leather casings which are packed with grease. These keep out 
























































GASOLINE AUTOMOBILES 


597 


the dirt and, consequently, lessen the wear, and also lubricate the 
moving parts of the joints. A secondary function of the casings is to 
render these joints noiseless. If a car is not equipped with them, it is 
advisable for the owner to purchase them. 

The shape of these casings, when opened out flat, would be not 
unlike that of two bottles with their flat bottoms set together, that 
is, narrow at the top and bottom and wider at the middle. All along 
both edges are eyelets for the lacing. The enlarged center fits around 
the joint, while the small ends encircle the respective shafts. To apply 
the casing, one end is placed around the shaft on one side of the joint, 
and the lace started; then the lacing proceeds, gradually drawing 
the ends together and around the joint. When this has been com¬ 
pleted, and before the last end is closed, the whole is shoved back 
along the first shaft a little way, and the center portion half filled 
with a heavy grade of transmission grease. This done, the glove is 
pulled back into place, and the work of lacing completed around the 
second shaft. Both ends should be laced as tightly as possible, while 
the middle part should be loose. Sometimes these housings will 
become worn and make a very annoying chatter on the road, even 
when they are not sufficiently worn to warrant replacements. Under 
such circumstances, the offending member may be wound with tire 
tape held firmly in place in addition to its adhesive power by means of 
a hose clamp, as shown in Fig. 458. The coupling is held tightly 
enough to prevent the rattle and chatter, but not enough to interfere 
with its action. While not a handsome job, it does the business, 
stopping the noise effectively. 

Rear Axle. Rear axles do such hard work and must stand up 
under such a large portion of the load carried in the machine that 
they offer many chances for wear, adjustment, or replacement. 

Truss Rods. Truss rods hold the wheels in their correct ver¬ 
tical relation to the road surface and to one another. If, through wear 
or excessive loading, the axle sags so that the wheels tip in at the 
top, presenting a knock-kneed appearance, the truss rods must be 
tightened up. Usually, they are made with a turnbuckle set near one 
end, a locknut on each side preventing movement. The turnbuckle 
is threaded internally with a right-hand thread on one end and a left- 
hand thread on the other, so that a movement of the turnbuckle draws 
the two ends in toward one another, shortens the length of the rod, 


598 


GASOLINE AUTOMOBILES 


and thus pulls the lower parts of the wheels toward one another, 
correcting the tipping at the top. 

To adjust a sagging axle, loosen both locknuts, remembering 
that one is right-handed and the other left. Then, with the wheels 
jacked clear of the ground, tighten the turnbuckle. A long square 
should be procured or made so that the wheel inclinations may be 
measured before and after. Placing the square on the ground or 
floor, which should be selected so as to be perfectly level, the turn- 
buckle should be moved until the tops appear to lean outward about 
i inch—some makers advise more. 

It should be borne in mind that even if the wheels and axle do 
not show the need of truss rod adjustment, if this rod be loose, it 
will become very noisy and rattle a great deal, as the rear axle sus¬ 
tains a great amount of 
jouncing. Moreover, this 
noise and rattle, if not 
taken up, will cause 
wear, which cannot be 
taken up. 

Disassembling Rear 
Construction. In disas¬ 
sembling the rear con¬ 
struction for purposes of 
adjustment or repair, the 
repair man should be 
careful to mark all parts. Those parts which have been running 
together for several thousand miles act better and with less friction 
than would those which have never run together, despite the fact that 
the duplicate parts are supposed to be alike and interchangeable. 
It is therefore suggested that separate boxes be provided for the parts 
taken from the two ends or sides. The method of disassembling is 
about as follows: Jack up the axle, replacing the jack with small 
horses or blocks of wood if possible. Take off the hub caps, then 
free the wheels and take them off. Disconnect the brake-operating 
rods and levers and remove them from the car, marking them care¬ 
fully. Spread the brake shoes apart, loosen the springs at one side, 
take out the springs, and then loosen and take out the brake 
shoes themselves. Remove the brake operating shaft with the cams; 



Fig. 458. Easy Method of Quieting Noisy Universal- 
Joint Housings 

Courtesy of “Motor World” 















GASOLINE AUTOMOBILES 


599 


then disconnect the spring bolts and jack up the chassis, using the 
spring for a support. Disconnect all torsion or radius rods and take 
oil the grease boot around the universal joint in the driving shaft. 
Open this joint and disconnect the shaft. Take this off, and if the 
spring bolts have been removed, the rear axle will be free. Pull it 
out from under the chassis, and, if desired, further disassembling may 
be done more easily with the member clamped in a vice or laid on a 


bench. 

Assembling. In assembling, almost the reverse of this process 
is followed, the parts going together in the opposite manner from 
that in which they were taken down. 

Noisy Bevel Gears. If the bevel gears in the rear axle are 
noisy, the time to fix them is when the axle is disassembled, as this 
is quite a job. In general, bevel gears make a noise because they 
are poorly cut, because they are not set correctly with relation to 
each other, or because the teeth have become cut, or chipped, by 
some foreign material which has been forced between them. 

In the first case, there is little the amateur can do beyond 
making the best possible adjustment and smoothing off any visible 
roughness. In the second case, it is simply a matter of setting one 
gear closer to or farther from the other by means of the adjustment 
provided. When the axle is disassembled, and all parts are readily 
accessible, it will be found that there is a notched nut on either side 
of each of the bevels; there should be a wrench in the tool kit to fit 
this. It is then a simple matter to move one outward and the other 
inward in either pair, according to which needs the adjustment. 
In case the teeth have become chipped, the projections should be 
smoothed down with a fine file, while the sharp edges of the cuts 
should be dressed in the same manner. 

Packard Bevel Adjustment. Although strictly a transmission 
trouble, the older Packard cars have the transmission located on the 
rear axle, and this position made the adjustment of the bevel pinion 
difficult. For another thing, the shaft is very short and hard to hold. 
If the sliding gear on the shaft is meshed with the internal gear 
attached to the other end of the bevel-pinion unit, the latter will hold 
firmly, but there will still be a little play between the teeth. It is 
necessary to take this up, as otherwise the repair man would mistake 
this play for play in the bevel driving gear. It can be taken up as 


GOO 


GASOLINE AUTOMOBILES 


follows: Take an old sliding-gear unit from one of these transmissions, 
remove one of the teeth and slide the gear into position for meshing 
with the space at the top between two teeth on the good gear. Drive 
a pin in where the tooth has been removed, and this will fix the two 
firmly together without a particle of play. Then, by removing the 
cover from the differential housing, the bevels can be tested for play. 
Eig. 459 shows the transmission, bevel gears, and axle parts, also the 
gear with the tooth removed and replaced by a pin, so that the whole 
process will be clear. 

Repair for Broken Spring Clips. The springs are held down on 
the axles by means of spring clips, which are simply U-shaped bolts 



[Fig. 459. Diagram of Packard Axle and Transmission to Show 
Adjustment of Bevel Pinion 

Courtesy of “Motor World” 


with the inside width of the U equal to the width of the spring. 
Occasionally, these will break when they cannot be replaced or new 
ones forged. Under such circumstances, a repair such as used by 
one man, shown in Fig. 460, will always get the car home or to a 
garage where a better one can be made. This method of repair 
consists of a pair of flat plates, one above the spring, the other below 
the axle, with holes drilled in the corners to take four long carriage 
bolts, which happened to be handy. The plates were put on, bolts 
put in and tightened up, and the car was ready to run. Although 
an I-section axle is shown, this method of repair would work just 
as well on a round axle or on one of any other shape. 







































































































































GASOLINE AUTOMOBILES 


601 


Lining Up Axles. In such a repair, however, the main thing 
is to get the rear axle lined up correctly, which is not an easy job. 
This may be done in the following manner: Get the car standing level 
on a nice clean smooth floor; hold a large metal square with a plumb 
bob hanging down over its short edge against the side of the frame. 
Move the square forward until the line just touches the rear axle at 
some set distance out from the frame, say 3 inches, as shown in Fig. 
461. Then notice the distance this line is forward from the rear end 
of the frame. In the sketch it is 16 inches. Transfer the square and 
plumb bob to the other side and repeat. Here it will be found that the 
distance from the rear end of the frame is either more or less. In the 
sketch it is shown at 18 inches; so the difference, 2 inches, shows that 
the axle is out of alignment 
that much or half that, 1 
inch at each end. 

This axle is straightened 
by loosening the spring bolts 
and pushing one side back 
the distance apparently 
needed, then fastening 
tightly and checking up. If 
not correct, try again, using 
judgment as to which side 
should be moved. When 
finally satisfied that the rear 
axle is square with the frame, 
it is well to check this against the center-to-center distance of the 
wheels on each side. This is done by setting the front wheels exactly 
straight and then measuring from the center of the right front to the 
center of the right rear wheel. Then go over to the other side and 
measure the center-to-center distance of the left wheels. The two 
axles should agree exactly. If they do not, the rear axle prusumably 
needs more adjustment for squareness. 

Taking Out Bend in Axle. A simple method of repairing an axle 
which has been bent, but a method which is only temporary in that it 
is not accurate enough to give a job which could be called final, is 
that indicated in Fig. 462. The axle was bent when the hub struck 
an obstruction in the road, and it had to be straightened immediately. 



Fig. 460. How Spring Clips Are Replaced 
in Emergency 

Courtesy of “Motor World” 









602 


GASOLINE AUTOMOBILES 


A short length of 2 x 4 timber was cut to be a tight fit between the 
upper side of the hub cap and the roof beam. Then a jack under the 



Fig. 461. Method of Checking up Rear-Axle Alignment with Square and Plumb Bob 


axle at the point of the bend was raised. As the jack raised the axle, 
and the wood beam held the hub down, enough pressure was exerted 

to force the axle to give at the 
bend and return as nearly as 
possible to its original straight¬ 
ness. It was a quick and easy 
repair of the rough and ready 
order, which served when time 
was worth more than anything 
else; but it is a method which 
would not be advised or recom¬ 
mended when there was suffi- 
cient time to properly 
straighten the axle. 

Locating Trouble. Many 
times, a car may be brought 
in for rear-axle repair on which 
the repair man cannot find any 
trouble. Many axles often 
develop an elusive hum, or 
grinding noise, which not only 
defies location, but is not con¬ 
tinuous. The writer had such 
a case brought to him at one 



Fig. 462. 


One Way of Straightening Rear 
Axle Quickly 








































































GASOLINE AUTOMOBILES 


603 


time, and was sure that the bevel gears were out of alignment and 
were cutting each other. It was a low-pitched whine which was 
not apparent at low r speeds, but began to be heard around 18 to 20 
miles an hour, and at times v r as very apparent. The noise was very 
annoying, but tearing down the rear construction showed absolutely 
no trouble; so the noise could not be at that point. Sometime later 
the noise was definitely located in a pair of w r orn speedometer 
gears on the right end of the front axle. 

A good way to listen to rear axle hums out on the road is to lay 
back over the rear end of the car, Fig. 463, with the head against 
the top of the seat and project¬ 
ing over slightly, and with the 
hands cupped in front of the 
ears, so as to catch every noise 
that arises. The larger sketch 
shows the general scheme, the 
small inset giving the method 
of holding the hands. When 
the sound arising from the axle 
is a steady hum, the gears are 
in good condition and well 
adjusted. If this sound is inter¬ 
rupted occasionally by a sharper, 
harsher note, it may be assumed 
that there is a point in one 
of the gears or on one of the 
shafts wLere things are not as they should be. • By trying the car 
at starting, slowing down, running at various speeds, and coasting, 
this noise can be tied to something more definite, some fixed method 
of happening. In advance of actual repair work, including tearing 
down the whole axle, the gears can be adjusted. This can generally 
be done from outside the axle casing and without a great deal of work. 
If the adjustment makes matters worse, it can be reversed, or if it 
improves the situation, the adjusting can be continued, a little at a 
time, until the noise gradually disappears. 

Checking Up Ford Axles. Many cases of Ford bent rear axles 
can be fixed without taking down the whole construction. The prin¬ 
cipal point is to find out how much and which way the axle is bent. 



Fig. 463. 


Listening for Rear-Axle Noises 









604 


GASOLINE AUTOMOBILES 


By removing the wheel on the bent side and placing the rig shown in 
Fig. 464 on the axle end, the extent of the trouble can be indicated by 
the axle itself. The iron rod is long and stiff, with its outer end 
pointed, and is fastened permanently to an old Ford hub. The 
rig is placed on the axle and held by the axle nut, but without the 
key, as the axle must be free to turn inside the hub. With the pointed 
end of the rod resting on the floor and with high gear engaged, have 
some one turn the engine over slowly, so as to turn the axle shaft 
around. As it revolves, the hub will be moved, and the pointed end 
on the floor will indicate the extent of the bend. By marking the 
two extreme points and dividing the distance between them, the 
center is found. Then a rod can be used as a bar to bend the axle, 
until the pointed rod end is exactly on the center mark. A little 

practice with this rig will 
enable a workman to 
straighten out a Ford rear 
axle in about the time it 
takes to tell it. 



Fig. 464. Diagram Showing Method of Checking 
Up Ford Axles 


BRAKES 

Function of Brake. 

Next to power, applied 
through the correct form of 
gearing, and its final suita¬ 
ble drive to the road wheels, 
nothing is of more importance than the ability to stop the vehicle at 
will. One medium through which this is done, and which ordinarily 
suffices, is the shutting off of the source of power—in this case, the 
gasoline and the spark which is used to ignite its vapor. This will not 
always suffice, however, for the ordinary car possesses the ability to 
run at a speed of 40 miles per hour or upward, and weighs from 2000 
pounds (one ton) upward to 4000 pounds (two tons). This combi¬ 
nation makes for a large force of inertia, which will result in the car 
running for many yards, even hundreds of yards, after the power is 
shut off. It is for this reason that we must have a mechanical 
means of absorbing this inertia, or of snubbing the forward move¬ 
ment of the car. This is the function of the brakes, as fitted to 
the modern car. 






















GASOLINE AUTOMOBILES 


605 


Engine as a Brake. Although disregarded in any summary of 
brakes, the engine is the best brake possible, granting that the driver 
knows how to get the best results without doing any damage. The 
ordinary engine has a compression of from 60 pounds to 70 pounds per 
square inch, which is practically the pressure available when it is used 
as a brake. Since this is more pressure than any other type, or form, 
of brake will yield, its usefulness is self-evident. 

Classification. Brakes are usually divided into two classes, 
differing mainly in location—the internal expanding and the external 
contracting. To these a third class should be added, because it par¬ 
takes of the nature of both, yet differs from each one. This is the 
railway type of brake with removable shoes of metal, differing from 
the band type in that no attempt is made to cover the whole or even 
the greater part of the circular surface, but simply a small portion of it, 
against which a shoe is forced with a very high pressure. Both the 
other types are subject to division into other classes, the first into 
three subdivisions according to operating means, viz, cam, toggle, and 
scissors action. 

Brakes are generally divided according to their location, as shaft 
and rear axle. The shaft brake at one time virtually went out of use, 
but it is now being revived. The marked swing toward the unit 
power plant, together with its simplification, lightening, and elimina¬ 
tion tendencies, has produced a situation where a brake drum just 
back of the power and gear unit can be operated by the hand lever 
and a very short rod. In this way much weight and many parts are 
saved. An indirect advantage is that the brake is more accessible. 
With the worm drive, there is a marked tendency back to the shaft 
brake, particularly on motor trucks. Again, in the last few years, 
some work has been done with pneumatic, hydraulic, and electric 
forms of brake. With air under pressure for starting, and with water 
or electricity as needed for starting or for other purposes, it is a simple 
matter to utilize the same agency for braking, providing such use does 
not add too much complication and, at the same time, that it 
will give a superior method of snubbing the forward movement of the 
car. In case none of these advantages are realized, there will be no 
particular advantage in adding new forms of brake. 

ExternaLContracting Brakes. This class of brakes is divided 
nto but two types, viz, single- and double-acting. In the first, an 


606 


GASOLINE AUTOMOBILES 


end of a simple band is anchored at some external point, while the 
other, or free end, is pulled. This results in the anchorage sustaining 
as much pull as is given to the operating end, that is, all pull is trans¬ 
mitted directly to the anchorage. This disadvantage has resulted 
in this form becoming nearly obsolete. 

Any brake of the true double-acting type will work equally well 
acting forward or backward. The differential brake, Fig. 465, 
shows this clearly. The external band is hung from the main frame 
by means of a stout link which is free to turn. The band itself 
is of very thin sheet steel, lined with some form of non-burnable belt¬ 
ing. The ends carry drop forgings, to which the operating levers are 
attached. These are so shaped that the pull is evenly divided between 
the two sides of the band. This will be made apparent by considering 

that a pull on the lever H will 
result in two motions, neither 
one complete, since each depends 
upon the other. First, there will 
be a motion of the upper band 
end B about the extremity of the 
lower one as a pivot, followed by 
a movement of the lower end, 
pivot and all, about B as a second 
pivot point. These two motions 
result in a double clamping action 
which is supposed to distribute evenly over the surface. In order to 
insure even distribution, the lining is grooved, or divided, into 
sections. 

Usually, chain-driven cars have a different brake location from a 
car with shaft drive. The chain-driven cars have three sets of brakes: 
one on the main shaft, one pair on the countershaft, and another pair 
on the rear wheels, as shown in Fig. 466. 

InternaLExpanding Brakes. While the contracting-band brake 
is well thought of, the internal-expanding form is rapidly displacing 
it, for the reason that experienced drivers think more of it. In Fig. 467 
will be seen a modern form of the internal brake, namely, the use of 
both brakes as internal, but placed side by side in the same drum. 
This is a tendency which seems to be gaining in favor. The car is the 
Owen Magnetic, one of the most expensive and luxurious; so the use 



Fig. 465. Brake on Main Shaft of 
Benz (German) Car 









GASOLINE AUTOMOBILES 


607 


I 


of side-by-side internal brakes here must be attributed to superiority 
rather than to a desire to save in money or in parts. 

A considerable number of foreign cars, which are used in moun¬ 
tainous countries, show a method of cooling the brake drums by means 
of external cooling flanges. In some makes, even a water drip is 
provided for extremely hilly country. 

More modern practice shows no tendency to place all of the eggs 
in one basket, both forms of brake being employed together and upon 
the same car, usually also upon the same brake drum, one set working 



upon the exterior, while the other works upon the inside. In Fig. 468, 
which shows the rear-axle brakes of the larger cars made by the 
Peerless Motor Car Company, this mechanism is plainly illustrated, 
both the brakes being shown, although the drum upon which they 
work has been removed. The parts are all named so as to be self- 
explanatory. In this construction, the inner, or expanding, band is 
operated by a cam. In the brake sets put out by the Timken Roller 
Bearing Company, of Detroit, Michigan, in connection with their bear¬ 
ings and axles, the toggle action is used, Fig. 469. The constructional 
drawings, Figs. 470 and 471, showing the brakes used on the Reo 
car, manufactured by the Reo Motor Car Company, of Lansing, 


















608 


GASOLINE AUTOMOBILES 


Michigan, indicate that this firm is partial to the cam for brake opera¬ 
tion, since these are used for both internal and external brakes, the 



B RAKE SHOE 


ANCHOR 


'BRAKE SHOES AMO 


BRAKE 


BEARING 


HUB 


AXLE SHAFT AND SPIDER 


BEARING \ 


BRAKE-CAMS 


\ \ HUB CAP LOCH 

n LOck n ujX hub nut 
LOCK WASHER 


AXLE NUT 


Fig. 467. Rear Axle of Owen Magnetic Car with Wheel Removed to Show Brakes 
Courtesy of Baker-R & L Company, Cleveland, Ohio 



■yre mAL srahb bang 


CIEV/S 


exrenm. bhakb band 




' pere/tAM. BMxe .isven. 


TCttHAf. B KAKB SHgf C AM 
/A aa*«£ snGrr 


Stre am: aaAxr hand an runn 


. Fig. 408. Peerless Rear-Axle Brake 

internal form having a split link connected to the toggle, while the 
external has a link movement in contracting much like that shown 
in Fig. 465, which is there explained in detail. 







































GASOLINE AUTOMOBILES 


009 


In general, however, when both brakes are placed on the rear 
wheels, one external and of the contracting-band type, and the other 


internal and of the expanding-shoe 
form, modern practice calls for a 
cam to operate the latter, oper¬ 
ating directly upon the ends of 
the two halves of the shoe, while 
levers operate the band so as to 
get a double contracting motion. 

Some modern brakes may be 
seen in Figs. 472, 473, and 474. 
The first shows a system such as 
just described; the secona shows 
a stiff metal shoe in both types; 
and the last a pair of shoes set 
side by side. In addition, the last- 
named includes a new thought in 



Fig. 469. Timken Double Rear-Axle Brake 




Fig. 471. Drawing Showing Method of 
Operating Reo Brakes 

Courtesy of Reo Motor Car Company, Lansing, Michigan 


Fig. 470. Section Showing Construction 
of Reo Brakes 


that the brake shoes are floated on their supporting pins, as shown. 
This makes the bearing of the shoes certain when expanded against 
every portion of the drum, as the shoes can float until they fit exactly. 





































































GIG 


GASOLINE AUTOMOBILES 


Double Brake Drum for Safety. A very important feature is 
pointed out in Fig. 472, namely, that of safety. Where both brakes 
work on a common drum, one inside and the other outside, the con¬ 
tinuous use of the service brake (whether internal or external) heats 
up the drum to such an extent that when an emergency arises calling 
for the application of the other brake it will not grip on the hot 
drum, being thoroughly heated itself. The double drum allows air 
circulation and constant cooling. 

Methods of Brake Operation. While it is generally thought that 
round iron rods are the universal means of brake operation, such is not 
the case. Many brakes on excellent cars are worked, as the illus¬ 
trations show, by means of cables. This idea is even carried so far 

t 



that brakes have been fitted to operate through the medium of ropes. 
Chains of small diameter have also been used, as well as combinations 
of rods, chains, cables, and ropes. 

A lever-operated braking system of a well-known medium- 
priced car is shown in the outline sketch, Fig. 475. In this system the 
forward part of each half is worked by rods moved by means of 
pedals, but the rear part of each half is actuated by means of cables. 
Cables have one advantage over rods in a situation like this—the 
diagonal pull with a stiff rod might, in time, act to pull the brakes side- 





















GASOLINE AUTOMOBILES 


611 



Fig. 473. Brakes and Rear Construction of Pierce Cars 
Courtesy of Pierce-Arrow Motor Car Company, Buffalo, New York 



Fig. 474. Side-by-Side Arrangement of Brakes on American Rear Axle 
Courtesy of American Ball Bearing Company, Cleveland, Ohio 































































































































































GASOLINE AUTOMOBILES 


012 

wise off their respective brake drums, the cable, being more flexible, 
gives less danger of this. 

This method of operation seems to be gaining favor because of 
its simplicity, which eliminates parts that add weight and gives 
immediate results when the parts are properly adjusted. The recent 
New York show revealed a surprising number of small and medium 
size cars with cable-operated brakes. An inspection of these cars 
showed a mechanical cleanliness which was lacking in many others of 
the same class on which an attempt was made to reduce braking rods 



Tig. 475. Layout of Brake-Operating System Using Cables 


and levers to a minimum, with consequent bent levers, bent or crooked 
lods, brakes worked from an angle, and other unmechanical ideas. 

bully as important as the operating means is the matter of 
equalizing the pull so that the same force is exerted upon both wheels 
at once, dhis action is influential in causing side-slip or skidding, 
which may result fatally, lo equalize the force was one reason for 
the use of cables, although the more up-to-date way is to attach the 
operating lever to the center of a long bar, to the extremities of which 
the brakes themselves are fastened. A pull on the bar is then divided 
into two different pulls on the brakes, the division being made 
automatically and according to their respective needs. This is an 



















































GASOLINE AUTOMOBILES 


613 


important point, and one that should be looked after in the purchase 
of a new car. * 

Brake Adjustments. In recent years much of the brake improve¬ 
ment has been that of making adjustments easier and of making the 
adjusting parts more accessible. This can be noted in such a case as 
the Locomobile, Fig. 472, where the special adjusting handle on the 
brake is carried to such a height as to make the turning of it an easy 
matter. Similarly, on the Pierce, Fig. 473, it will be noted that 
there is provision for increasing or decreasing the closeness of the 
shoes to the drum, which is easily accessible. 

Brake Lubrication. As for the actual brake surfaces, there is no 
such thing as lubrication. The surfaces should be kept as dry and 
clean as possible. If grease or oil gets out from the axle or other 
lubricated parts onto them, there is sure to be trouble. The operating 
rods and levers, however, should have fairly careful lubrication, for 
which purpose the best makers provide grease or oil cups at all vital 
points. If these be neglected, a connection may stick, so that when 
an emergency arises the brake will not act properly and an accident 
may result. 

Recent Developments. In the last few years, the only new 
ideas advanced in the way of brakes concern front-wheel braking 
and electric brakes. The former were used quite extensively abroad 
in 1913, but in 1914 they seemed to drop back; this, too, despite the 
fact that the Grand Prix race of the latter year showed in a marked 
manner the need for and special application of front-wheel brakes to 
racing and high-speed cars. 

Electric Brakes. A very efficient and compact brake, appli¬ 
cable with a small amount of work to any chassis having a storage 
battery, is the Hartford, shown in Fig. 476, while Fig. 477 shows the 
operating lever as it is placed beneath the steering wheel, and Fig. 478 
shows the wiring system. This brake consists, in substance, of a 
small reversible electric motor, to which a 100 to 1 worm reduction is 
attached. Attached to the drum is a cable, which is fastened to the 
usual brake equalizer. Turning the current into the motor from 
the storage battery rotates the drum, winds up the cable, and applies 
the brake. The complete outfit weighs but 35 pounds. The motor has 
a slipping clutch set to operate at 1000 pounds pull, at which it draws 
40 amperes of current from the battery for two-fifths of a second. 


GASOLINE AUTOMOBILES 


G14 



Fig. 476. Exterior of Motor Which Forms Central 
Unit of Hartford Electric Brake 
Courtesy of Hartford Suspension Company, 
Jersey City , New Jersey 



Fig. 477. Hand Lever on Steering Post for 
Operating Hartford Electric Brake 



BATTERY. 


Fig. 478. Wiring Diagram for Hartford 
Electric Brake 


Tn use, it replaces the emer¬ 
gency hand-operating lever, 
and is said to he able to pull 
a heavy car going 50 miles an 
hour down to less than 15 in 
a distance of less than 35 
feet. The pull is so great 
that the brake drums are 
oiled to prevent heating and 
possible seizing. 

Hydraulic Brakes. On 
the newer Knox tractors, a 
brake of very large size is 
made even more powerful by 
hydraulic operation. This 
brake is shown in Fig. 479. 
At the left will be seen the 
usual brake lever attached to 
a small piston in a chamber 
full of liquid. This chamber 
communicates through the 
medium of a valve normally 
held closed by a spring, with 
a passage above, and that, in 
turn, communicates with the 
pipes leading to the brake- 
operating cylinder. This cyl¬ 
inder has a stout rod attached 
to a good size plunger, back 
of which the liquid (oil) is 
introduced. When liquid is 
forced in, the plunger moves 
forward, forcing the rod out 
and, through connecting rods 
and levers, applying the 
brakes. As will be seen in 
the drawing at the right, 
these brakes, which are of the 






















GASOLINE AUTOMOBILES 


015 


internal-expanding type, are exceptional in size and work against 
steel drums attached directly to the wheel spokes. 

When the lever is drawn back in the usual manner, liquid is 
forced upward through the top passage to and through the pipes 
into the other cylinder, forcing the plunger to move, and, through the 
movement of the plunger, the brakes are applied. The return of the 
fluid is not shown, but it is assumed that this is through a simple pipe 
connection from the plunger cylinder to the hand-operated piston with 
a check valve. Should the initial movement of the lever fail to apply 


the brakes sufficiently, the driver can let the lever come forward and 
then pull it back again; in so doing he will take into his lever cylinder 



Courtesy of Knox Motors Company, Springfield, Massachusetts 

more liquid from below without releasing the brakes. Then, when 
this extra quantity is forced through, the plunger is moved even 
farther forward, and the brakes applied more forcibly. The brakes 
are 20 inches in diameter by 6J inches wide. 

Vacuum Brakes. The latest development in the line of braking 
systems is the Prest-O-Lite vacuum brake. This brake consists of a 
controlling valve, a vacuum chamber, piping from the inlet manifold 
to the valve and thence to vacuum chamber, and a foot button or finger 
lever on the steering post to operate the valve and thus put the 
system into use. The rod in the vacuum chamber is connected up 
to the service brakes, the system thus taking the place of the usual 
pedal and foot operation. The chassis sketch, Fig. 480, shows this 

i 















































616 


GASOLINE AUTOMOBILES 


in plan, A being the controlling valve, BB the tubing from the inlet 
manifold to the controlling valve and from it to the vacuum chamber 
C. The rod D from the chamber will be seen connected to the 
service-brake rods and levers. 

In Fig. 480 the method of operating the system is not shown, but 
in Fig. 481 the foot lever can be seen with its connections. When 
this is pressed, the controller valve is opened and the engine, as it runs, 
draws air out of the chamber C in back of the plunger, gradually 
creating a vacuum, so that the plunger is forced to move forward to 
compensate for this. As the plunger carries a tail rod projecting 
through the end of the cylinder, and as this rod is connected up to the 
braking system, but with a big leverage, the movement of the plunger 



Fig. 480. Chassis Plan Showing Application of Prest-O-Lite Vacuum Brake 
Courtesy of Prest-O-Lite Company, Indianapolis, Indiana 


applies the brakes. The amount of brake application depends upon 
the amount of suction, and that is governed by the amount the valve 
is opened by the finger lever or foot button. Consequently, with this 
new brake, the bucking effort can be varied to suit the conditions. 

It is said that the leverage arrangement is such that 10 pounds 
per square inch in the intake manifold will produce 1000 pounds 
braking effort at the rear wheels. This means that the brakes could 
be used with the engine running very slowly. The system is applied 
to the service brakes because a brake is sometimes needed when the 
engine is not running, as when coasting down a hill with the engine 
shut off and clutch out, or with the car standing and engine shut off, 
etc.; also because it is the most used system, and it is felt that the 
simple finger pressure and gradual or instantaneous application 






































































































GASOLINE AUTOMOBILES 


617 


possibilities of the new form make it more desirable as a service or 
running brake. 

Whatever advantages may develop in the use of these special 
types, it is certain that the next few years will see considerable 
improvement in braking, so that a greater force may be applied more 
quickly, and thus act to prevent a large pail of the accidents for 
which automobile owners and drivers are now unjustly blamed. 

BRAKE TROUBLES AND REPAIRS 
Dragging Brakes. Probably the first trouble in the way of 
brakes is that of dragging, that is, braking surface constantly in 



Fig. 481. Foot Button for Operating Vacuum Brake 


contact with the brake drum. This should not be the case, as springs 
are usually provided to hold the brake bands off the drums. Look for 
these springs and see if they are in good condition. One or both of 
the brake bands may be bent so that the band touches the drum at a 
single point. 

Another kind of dragging is that in which the brakes are adjusted 
too tightly—so tightly, in fact, that they are working all the time. 
In operating the car, there will be a noticeable lack of power and 
speed, while the rear axle will heat constantly. This can be detected 
by raising either rear wheel or both by means of a jack, a quick 









618 


GASOLINE AUTOMOBILES 


lifting arrangement, or a crane, and then spinning the wheels. If 
the brakes are dragging, they will not turn freely. 

All that is needed to remedy this trouble is a better adjustment. 
For the new man, however, it is a nice little trick to adjust a pair of 
brakes so that they will take hold the instant the foot touches the 
pedal, that they will apply exactly the same pressure on the two 
wheels, and yet will not run so loose as to rattle nor so tight as to drag. 

Dummy Brake Drum Useful. Where a great deal of brake 
work is to be done, particularly in a shop where the greater part of 
the cars are of one make, and the brakes all of one size, a great deal 
of time and trouble can be saved by having a set of test drums. An 
ordinary brake drum with a section cut out so that the action inside 
may be observed is all that is necessary, except that it should be 
mounted suitably. As shown in Fig. 482, it is well to fit a pair of 

handles to the brake drum 
to assist in turning the 
drum when the adjustment 
is being made. The real 
saving consists of the work 
which is saved in putting 
on and taking off the heavy 
and bulky wheel each time 
when the adjustment is 
changed. The test drum 
is put on instead, and being small and light and equipped with handles, 
it is easily and quickly lifted on and off. This enables the workman 
to make a better and more accurate adjustment than he would when 
the heavy wheel had to be handled, while the cut-out section enables 
him to see the inside working also,and thus correct any defects or 
troubles at this point. 

To Stop Brake Chattering. It is claimed that the chattering 
of brakes is caused by having the brake lining, particularly of internal 
hand brakes, extend over too large a portion of the circumference of 
the drum. The result is that with a well-adjusted system, as soon as 
force is applied, the lining close to the operating cam and that on 
the opposite side close to the pin on which the brake shoes are 
pivoted jumps against the drum and then away from it. This 
jumping of the brake shoe, which is the result of too much lining, is 









































GASOLINE AUTOMOBILES 


019 




what causes the chattering. If the lining is cut away for about 30 
degrees on either side of a line drawn from cam to pivot pin, as shown 
in Fig. 483, it is said that this chattering will stop immediately. 
If further trouble of the 
same kind results, bevel off 
the outside ends of the lining 
at the two 30-degree points. 

A number of sugges¬ 
tions in the way of possible 
brake troubles, particularly 
on the side-by-side form of 

t j 

internal-expanding brakes, 
are indicated in Fig. 484. 

This shows a semi-floating 
form of rear axle wi +1 Tie 
two sets of brakes and oper 
ating shaft and levers. A 
number of suggestions are offered for this form, tne most important 
of which is: “Renew worn brake lining and broken cr loose rivets.” 

When a brake lining is worn, the proceeding is much the same 
as with a clutch leather, with the exception that whereas the latter 

Clear? (§■ refill cups 

43rake operating levers 
should be 

Operating 
rods roust 
fit dose 

Truss rods 
trust betidht 


Fig. 483. Method of Eliminating Brake Chattering 
on Internal-Expanding Brakes 


T5 worn brafie lining 
S* broken or loose 


rivets 


ioes rot 


nut 


to shudder. 


make, wash 


Td fit 


er 


Isver spring seats with canvas or leather 


Fig. 484. Brake Troubles Illustrated 


must have a curved shape, the former can be perfectly straight and 
flat. This simplifies the cutting; but most brake linings are made of 
special heatproof asbestos composition which is made in standard 
widths to fit all brakes, so the cutting of leather brake bands is not 
often necessary. 



























































620 


GASOLINE AUTOMOBILES 


Eliminating Noises. Many times the brake rods and levers 
wear just enough to rattle and make a noise when running over 
rough roads or cobblestone pavements, but hardly enough to war¬ 
rant replacing them. The replacement depends on the accuracy 
with which they work, the age and value of the car, and the attitude 
of the owner. In a case where the owner does not desire to replace 
rattling rods, the noise can be prevented by means of springs, winding 
with tape, string, etc. 

If the rod crosses a frame cross-member or is near any other 
metal part, and its length or looseness at the ends is such that it can 

be shaken into contact there, a rattle 
will result at that point. This can 
be remedied or rather deadened by 
wrapping one part or the other. For 
this purpose, string or twine can be 
used as on a baseball bat or tennis 
racket handle, winding it together 
closely so as to make a contiguous 
covering. Tire or similar tape may 
also be utilized. When this is done, 
it is necessary to lap one layer partly 
over the next in order to keep the 
whole tight and neat. It has the ad¬ 
ditional advantage of giving a greater 
thickness and thus greater resistance 
to wear. If none of these remedies 

stretching Bnfke^Linfngsb^foreA^uactiment are available or sufficient, burlap in 
Courtesy of “Motor World” strips or other cloth may be used, 

putting this on in overlapping layers the same as the tape. 

The springs should be put on in such a way as to take up the 
lost motion and hold the worn parts closer together. The rattle 
occurs when the movement of the car alternately separates and pulls 
together the two parts, a noise occurring at each motion. The 
spring should be put on so as to oppose this motion, acting really 
as a new bushing or pin, the pull coming first upon the spring and then 
upon the bushing or pin. 

Stretching Brake Lining. Brake lining should be put on as 
tightly as possible, and the knowledge of this, combined with the 






GASOLINE AUTOMOBILES 


621 


Cutter 


difficulty of doing it by hand, makes the stretching device shown in 
Fig. 485 particularly valuable when much brake relining is to be done. 
This is a simple pulling clamp, which is attached to one end of the 
lining after the first end has been riveted in place. Then it is 
attached to the end of the shoe, and the nut tightened so as to stretch 
it. When it has been stretched sufficiently, the other rivets can be 
put in, or the shoe and band with the stretches in place can be laid 
aside for a while to stretch it fully before fastening. Obviously, this 
is applicable only to the internal- 
expanding form, but the hook 
and clamp can be used on any 
size or type of expanding brake. 

Truing Brake Drums. When 
both inside and outside surfaces 
of the brake drum are used, it is 
highly important that both be 
true. Since they do not stay that 
way long, the repair shop should 
be equipped to true them up 
quickly. A truing device is shown 
in Fig. 486, with the wheel and 
brake drum in place on it. One 
feature of the device is that brake 
drums need not be removed from 
the wheel. The device consists 
of a metal base having a strong 
and stiff wooden pier with a hori¬ 
zontal arm the exact size of the 
axle end mounted on it. The 
wheels are placed on the arm and 
rest on it the same as on the axle when on the car. The tool is 
double, with two ends, one of which cuts the inside surface of the 
drum, while the other cuts the outer surface. At the center this tool 
is attached to a heavy casting, bored out to slide over the shaft and 
with a key fitted into a keyway in the shaft to prevent the tool from 
rotating. The end of the arm is threaded, and a large nut with two 
Jong arms is screwed up against the tool at the start, and then it is 
used to feed the latter across the work. 



Metal Base 


Fig. 486. Apparatus for Truing Inside and 
Outside of Brake Drum in Place on Wheel 
Courtesy of “ Motor World ” 

































622 


GASOLINE AUTOMOBILES 


/ 

This is subject to a number of modifications to fit it to the various 
sizes and shapes of brake drum. Another method is to use the lathe, 
provided the shop is equipped with a lathe large enough. By making 
a mandrel the same as the axle spindle and having a pair of dummy 
bearings to place on it, the brake drum can be slipped on to the 
mandrel, and the whole put right into the lathe. The surface, either 
internal or external or both, can then be trued up exactly as if the 
drum were on the axle. 


WHEELS 

Broadly speaking, there are but two kinds of wheels according 
to the service each is to render, pleasure-car wheels and commercial- 
car wheels. The former may be further subdivided into wood, wire, 
and spring wheels; while the latter may be divided into wood, steel, 
and spring wheels. Some of the commercial vehicle wheels are 
further divisible, as steel wheels into sheet steel and cast steel; 
wood into spoked and solid; and spring wheels into various types. 

Wheel Sizes. Wheels are used on automobiles, in combination 
with the tires, to afford a resilient and yielding contact with the 
surface of the road, so that people may ride with comfort. Therefore 
a wheel whose size is such as to yield the most comfort to the car 
occupants with due regard to its cost relative to the cost of the vehicle 
is the wheel to use. The cost of the wheels themselves, however, 
is so small in comparison with the cost of the pneumatic tires which 
are used on them as to be completely overshadowed by the latter. 

Where comfort is sought as the prime requisite, cost becomes an 
accessory. The larger the wheel used the better the car will ride, 
and the greater will be the comfort of the occupants. This state¬ 
ment can be proved, although the gradually increasing sizes of wheels 
and tires as used on the best cars, both here and abroad—advancing 
from the early 26 and 28 X 3-inch tires, to as high as 38x5J-inch 
tires, and freaks up to 48 X 12-inch—should be sufficiently convincing. 

Advantages of Large Wheels. A graphical demonstration of the 
difference between the action of the large and small wheel to the 
advantage of the former is shown in two drawings, Figs. 487 and 
488. Fig. 487 presents the case of wheels passing over a common brick 
4 inches, wide by 2 inches high, and Fig. 488 shows the action in 
passing across a small rut in the surface of the road, 8 inches wide 


GASOLINE AUTOMOBILES 


623 


by li inches deep. In both cases, A shows the 28-inch wheel and B 
shows the 40-inch wheel. Both instances, too, have been selected at 
random, and not so chosen as to favor either wheel. It would have 
been possible to so select the sizes of both obstruction and depression 
as to make out a stronger case. 

The height of the brick being 2 inches the wheel must rise that 
distance, whatever its diameter, but in the case of the 28-inch wheel, 
this rise of 2 inches is largely relative to the wheel diameter being 
one-fourteenth, or 7 per cent. In the case of the larger wheel of 
40-inch diameter, the rise is again 2 inches, but it is now one- 
twentieth of the wheel diameter, or 5 per cent. In the case of the 



smaller wheel, the rise is distributed over a length of about 18.48 
inches from the moment when the forward edge strikes the 
obstacle to the moment when the last part of the tire leaves the 
last edge of the brick. If this rise were evenly distributed over 
this distance, rising as an arc of a circle, its radius would be slightly 
over 22 inches. 

Considering the 40-inch wheel under the same circumstances, it 
performs the act of rising and falling 2 inches in the longer distance 
of about 21.5 inches, the radius of this rise being 38.75 inches. It is 
obvious that the latter is a much easier rise than the former, the 
lift being distributed over a length 16 per cent greater. Similarly, 
with the descent from the high point to the surface of the road again, 

















































624 


GASOLINE AUTOMOBILES 


this more gradual rise and fall convert the surmounting of the 
obstacle from a sharp upward bump and downward jounce into an 
easy and not unpleasant swinging up and down. 

A drop into a hole, as illustrated by Fig. 488, shows the bene¬ 
ficial effect of the large wheel better, perhaps, than does the rolling 
over a rise. A rut in the road 8 inches across, into which the two 
wheels drop in passing, is shown. At A, the 28-inch wheel is seen to 
drop the considerable amount of -fa inch, while at B the 40-inch 
wheel drops but f inch into the same hole. Evidently the larger 
wheel has an advantage in so far as passing over obstacles or holes 
is concerned. 

Again, on account of its larger radius, the arc of the larger 
wheel is flatter and has more length of tread in contact with the 



Fig. 488. Diagram Showing Advantage of Large Wheels in Passing over Depression 


surface of the ground, this being particularly noticeable on rough 
roads. Not alone does this mean added adhesion to the ground and 
thus lessening driving effort to propel the same car, but it also means 
a greater resistance to side slip or skidding, thus conserving the 
power and increasing the safety of the occupants. Other arguments 
could be offered in favor of large tires for easy riding, but those 
given should suffice. 

PLEASURE=CAR WHEELS 

Wood Wheels. Wood wheels are the most common form for 
pleasure cars in this country, being almost universal. Ordinarily, 
they are constructed of an even number of spokes, which are tapered 
at the hub end and rounded up to a small circular end with a shoulder 
at the rim, or felloe, end. Fig. 489 shows this construction, A being 

















GASOLINE AUTOMOBILES 


G25 


the felloe on which is the rim B, and R is the spoke which, at the hub 
end, tapers down to the wedge-shaped portion P. This matches up 
to the wedge-shaped ends of the other spokes, so that when the 
wheel is assembled they form a continuous rim around the central 
or hub hole. 

The spokes are held at 
their inner ends by metal 
plates and by through bolts, 
which are set at the joints 
between the spokes so as to 
pass equally through each 
spoke, as shown at I). Not 
pnly do these bolts hold the 
spokes firmly to the wheel, 
but they have an expand¬ 
ing, or wedging, action 
tending to make the center of 
the wheel very rigid. 

The outer end of the spoke has a shoulder E and a round part C, 
which fits into a hole bored through the felloe. To prevent the 
felloe coming off after the spoke is in place, the spoke is expanded 
by means of a small wedge driven into it from the outside, as shown 
at F. In this wav, the wheel is 
constructed from a series of com¬ 
ponents into a strong rigid unit. 

Such wheels wear in two 
places, at the inner and at the 
outer ends of the spokes. The 
remedy in the latter case is to 
withdraw the small wedge and 
insert a larger one in its place. 

At the hub end, when wear occurs, 
this, too, must be taken up by 
means of wedges. Fig. 490 shows 
a method of doing this when the hub has no bolts at the 
joints. A false steel hub A is driven into the hub hole, after 
which wedges of steel are driven in between the wedge-shaped ends 
of the spokes. For slight cases of wear and squeaks, the wheel may 




Fig. 489. Construction of Wood Wheels 


































































C>20 GASOLINE AUTOMOBILES 

he soaked in water, which will cause it to swell, taking up all of 
the space. 

There are various modifications of this, nearly all of them 
changing the hub end of the spoke. In the Schwartz wheel, a patented 
form, each spoke is made with a tongue on one side of the wedge- 
shaped part and a groove on the other. In assembling the wheel, 
the tongue of each spoke fits into the groove of the spoke next to 
it, thus rendering the whole hub end of the wheel, when assembled, 
a stronger unit, being stronger in two directions, one of them of 
more than ordinary value. In driving the tongue into the groove, 
the wheel is rendered strong in a radial direction, but, when the wheel 



is entirely assembled, the tongue-and-groove method leaves it very 
strong to resist side shocks, a point in which the wood wheel is weakest. 

Staggered Spokes. As mentioned above, the wood wheel has 
little lateral strength, nor can it ever have, from the very nature of 
its construction, except in unusual cases, like the Schwartz patent 
wheel just described. A method of increasing the lateral strength 
somewhat is that of using staggered spokes, these being alternately 
curved to the outside and to the inside, as shown in Fig. 491. This 
gives one set of half the spokes forming a very fiat cone with its 
apex, or point, at the inner side of the hub, while the others form 
another cone with its apex at the outside of the hub. Each one of 























































GASOLINE AUTOMOBILES 


027 


these conical shapes is stronger to resist stresses from the side on 
which the point is located than would he the same number of spokes 
set flat. Hence, the staggered-spoke wheel has the advantage over 
the ordinary type in that it has greater strength from both sides. 
In the figure, A is the iron hub, B the felloe, Ci the right-hand and 
C 2 the left-hand spoke, and D the steel rim for the tire. This is a 
12-spoke wheel, 6 of the right-hand spokes C\ and 6 of the left-hand 
spokes C 2 . The section shows how these pass alternately to the one 
side or to the other, forming the strong cone shape. 



Fig. 492. Section of Steel 
and Wood Wheel 



Fig. 493. Complete Steel and Wood 
Truck Wheel 


Another method of handling this problem in a somewhat similar 
manner is the use of double sets of spokes, the spokes, however, being 
in two different planes separated a considerable distance at the hub. 
Of a necessity using the same felloe, the outer ends must be in the 
same plane. Fig. 492 shows a drawing representing a section through 
the center line of the wheel, while Fig. 493 shows a photographic 
reproduction of it. 

In Figs. 492 and 493, A represents the steel rim on the felloe 
F, the latter being of metal in this case, as is also the wheel so it 

























G28 


GASOLINE AUTOMOBILES 


may be disassembled. The spokes R have a tubular end piece of metal 
G, which is set over the rounded end of each spoke and fits into a 
hole in the felloe. I and S are, respectively, the inner and outer 
parts of the hub, which are held together and to the spokes by means 
of the bolts N. Z is the hub cap, while U and V are filler pieces 
aiding in the dismantling process. The strength of the wheel is self- 
evident, but it is difficult to see the advantage of the disassembling 
feature, as a stress or strain which would break one spoke, would, in 
almost every case, break practically all of the spokes, thus neces¬ 
sitating a new wheel instead of new spokes. 

Wire Wheels. Many of the little details of the automobile 
were inherited from its predecessor, the bicycle. x4mong these may 
be mentioned the wire wheel. Practically all bicycle wheels were 

and are of the wire-spoked type, 
and this same form of wheel was 
used on all earlier automobiles. 
It had no strength in a sidewise 
direction, nor did it, in fact, have 
much of anything to recommend 
it except its light weight. For 
this reason, it failed in automobile 
service, and received a setback 
from which it has even now not 
wholly recovered. 

Early Bicycle Models. Fig. 494 shows an early type of wire 
wheel for automobiles, its construction indicating clearly its bicycle 
ancestry. The spokes were set into a casting, which formed the hub, 
and into the steel rim by means of a threaded sleeve, the head on 
each end of the spoke resting on the inner end of the sleeve. The 
sleeves were screwed in and out to adjust the tension of the spokes. 
This tension was usually considerable, thus reducing in part the 
ability of the wheel as a whole to resist side stresses, for the piece 
already in tension could not be expected to sustain additional ten¬ 
sion, or compression, or a combination of either with torsion, accord¬ 
ing to the way the force was applied. Then, too, the casting for 
the hub was wholly unsuited to resist stresses, and the distance apart 
of the spokes at the hub was not sufficient, making the cone so very 
flat that it had very little more strength than a perfectly flat wheel. 



Fig. 494. Hub Details of Bicycle Wheel 



























GASOLINE AUTOMOBILES 


629 


Following the failure of wire wheels, there was a rapid change 
to wood wheels, which were almost universal for several years. 
Soon after this change was made, there was an increase in the size 
and pov ei of automobiles, which, in turn, was followed by a demand 
foi lessened weights. In the meantime, makers of wire wheels, 
knowing their faults, began to re-design in order to eliminate them. 
Their success is best evidenced abroad, where about one-half of the 
French and more than two- 
thirds of the English cars, 
in addition to over seven- 
eights of the racing cars 
in both countries, are now 
, equipped with wire wheels. 

N e w Successful 
Designs. This result has 
been brought about by a 
realization of the previous 
defects and their elimina¬ 
tion. Thus, no more cast 
hubs are used, drawn or 
pressed steel of the highest 
quality and greatest 
strength being used instead. 

The spokes have been car¬ 
ried out farther apart at 
the hub, obtaining a higher 
cone and thus a stronger 
one. Spoke materials are 
better and stronger, besides 
is, larger spokes and larger numbers of spokes per wheel, in some 
cases a triple row of spokes being used in addition to the ordinary 
two rows. This additional row acts as a strengthener and stiffener 
much like the diagonal stays on a bridge. Fig. 495 shows a set of 
double-spoke wire, triple-spoke wire, and interchangeable wood 
wheels side by side for comparison, while in Fig. 496 is presented 
a recent triple-spoke front wheel in detail. 

In the former figure, the relative depths of the various cones 
and their corresponding strengths are made evident, being side by 




Fig. 495. Sections of Double and Triple Steel and 
Wood Spoke Wheels 

being used in greater quantities, that 












































030 


GASOLINE AUTOMOBILES 


side. In this comparison, it will be noted that the new triple-spoke 
wheel has a much longer outer cone than the double-spoke wheel, 
while, on the other hand, the inner cone has been flattened. The 
triple spoke has a greater depth, considering the set of them as an 
additional cone, than has the inner cone in the double-set wheels. 

In examining closely the older double-spoke form and the newer 

triple type, it will be noted, also, how the 
wheel itself, or rather the tire and rim, 
have been brought closer in to the point of 
attachment, thus rendering the whole con¬ 
struction stronger arid safer. In Fig. 495, 
it will be seen that the center line of 
both tire and rim passes midway between 
the inner and outer ends of the hub on 
double-spoke wheels, while on the triple 
form it is even with the inside end of the 
inner hub, being, in fact, farther in than 
is the case with the wood wheel. One 
thing will be noted in all these spokes, 
regardless of number, position, or inclina¬ 
tion, and that is that their ends present a 
straight head. On the older bicycle spokes, 
the diagonal-spoke head was a great source 
of weakness, tending to create failure at 
the outset. The modern wire wheel is so 
constructed as to do away with this fault. 
By actual tests, the wire spoke—not the 
stronger triple spoke but the double spoke— 
has been found to have the following 
advantages: lighter weight for the same 

Fig. 496 . Details of Triple-Spoke carrying capacity; greater carrying capac- 
Front \\heel ity for equal weight; superior strength from 

above or below in the plane of the wheel; lower first cost (it is doubtful if 
this will hold good for the newer triple-spoke forms); and, in addition, 
tests have proved superior strength in a direction at right angles to 
the plane of the wheel. So marked is the difference in weight of the 
two that five wire wheels are said to be lighter in weight than four 
wood wheels of equal carrying capacity. 

































GASOLINE AUTOMOBILES 


G31 


All these arguments in favor of wire have been built up one by 

one, for much prejudice had to be removed. In spite of this, however, 

the wheel is slowly but surely building up a reputation and a long 

list of friends. Since, even now, England and the Continent continue 

to set the fashion in automobiles, it is not too much to expect to 

see wire-spoke wheels in common use in the United States in a few 

years. In fact, the dozen manufacturers 

offering this wheel in 1914, with ten more 

giving it as an option, have been increased 

to about forty who are fitting it regularly, 

with perhaps fifty or more offering it as an 

* 

option in 1915. In fact, almost any car 
maker in the country will fit wire wheels 
for a slight additional charge. 

For 1917 some 20 odd makes of cars 
are offered with wire wheels as * regular 
equipment, and about 25 more offer this 
as an option without extra charge. As 
there are about 190 cars on the market, 
the former represents 10.5 per cent, and 
the latter 13.2 per cent of all makes; the 
two together total 23.7 per cent, or less 
than one-quarter. However, these figures 
do not quite indicate the relative popu¬ 
larity of wire wheels. 

Wire Wheels Much ' Stronger. , The 
increase in the use of wire wheels has 
been brought about by better designs; 
greater attention to the details of manu¬ 
facture, assembly, and use; but primarily 
by the greater strength which has been 
built into the wire wheel. One way in 
which this has been done is by rearrange¬ 
ment of the spokes as, for instance, the triple-spoke form just 
described and shown in big. 409. Another and latei form is the 
quadruple-spoke wheel as seen in Fig. 497. This is made and sold by 
the General Rim Company, Cleveland, Ohio, and is called the G-R-C 
wheel. As the sketch indicates, it has all the features of demount- 



Fig. 497. G-R-C Quadruple- 
Spoke Wire Wheel 



















632 


GASOLINE AUTOMOBILES 


ability, etc., of other wire wheels, the notable differences being the 
spoke arrangement to give strength and the form of rim—a patented 
form to be described in detail later. 

By comparison with Fig. 496, it will be noted that a double 
triangular section is formed in the G-R-C, the inner spokes forming the 
inside of the hub and the outside of the hub forming one triangle, 
while the outer spokes from each form the other. In Fig. 496, it 
will be noted that there is but the one triangle and a straight row 
of “spokes. 

Sheet=Steel Wheels. The sheet-steel wheel is really a form of 
wire-spoke wheel, with an infinite number of spokes joined together. 
It has many advantages, some of which might be mentioned as 
follows: strength, lightness, low first cost, low cost of maintenance, 
and cleanliness. To take them up in order, the strength of two steel 
plates set a few inches apart in a somewhat triangular form with 
the base toward the hub and well attached at the center and at the rim 
of the wheel, is self-evident. Aside from the natural strength of the 
steel plates—far in excess of the wire spokes—or round wood spokes, 
there is the strength of the triangular form. A strong connection at 
the top and at the bottom makes the whole construction very similar 
to a structural form. This shape closely resembles a box girder, 
having great resisting strength in all directions. 

The light weight of the steel wheel comes from the thinness of 
the steel plates which are used, and similarly from the thin and light 
connecting members, either top or bottom. In Fig. 498 the junction 
at the top is seen to be nothing more than the steel rims for the tire, 
thus doing away with the usual felloe or substitute for it. In this 
figure, the wheel is seen to consist of the hub made with two flanges, 
to which the side sheets are bolted; the brake drum I bolted to the 
sheet on the inside, midway up its height; the steel rim mentioned 
before; and the bolts and rivets necessary to join the parts. At 
the hub, bolts are used to allow of dismounting the sheets in case of 
damage, for replacement or otherwise. At the rim, however, the 
plates are riveted to the rim, and riveted together. 

Low first cost is brought about by the simplicity of the wheel. 
The wheel consists of the usual rim, not counted in the wheel cost, 
and two pressed-steel sheets flanged at the top, with a few holes 
punched in them. These sheets are very cheap to make, while the 


GASOLINE AUTOMOBILES 


633 


hub construction is much cheaper than the ordinary hub, for the 
reason that there are usually two parts where this construction 
requires but one, and this a very simple one needing little machining. 
Low maintenance cost is brought about by the rigidity of the whole 
construction; the few parts, which make few to replace or even to 
wear; the cheapness of these parts, when replacement is necessary; 
and the well-known strength and long life of sheet-steel plates. 

On the score of cleanliness, it may be said that this is one of 
the drawbacks of the wire-spoke wheel, cleaning between and around 



the spokes being very difficult, if not actually impossible. The 
large number of spokes makes the hub inside of the spokes impossible 
to clean, whereas, with the sheet-steel wheel, the cleaning consists 
in merely turning a hose on the sides of the wheel, the cleaning of 

the hub being entirely unnecessary. 

It will be noted, too, in this illustration that the wheel has 
considerable spring, or should have, in a vertical direction. It is 
claimed for this type of wheel that this springiness is an added 
advantage as it allows the use of solid or cushion tites, and thus 











































































634 GASOLINE AUTOMOBILES 


eliminates the troublesome pneumatic tire with its puncture and 
blowout possibilities. For commercial-car use, all of the advantages 
just mentioned are of double worth, for which reason the steel wheel 
is making great strides forward on commercial cars. Where the 
springiness of the wheels is not so desirable as strength, the sheet- 
steel plates may be replaced with either pressed- or cast-steel side 
members on which strengthening ribs are formed. The sides of the 
wheel have holes HII through them which are provided for ventila¬ 
tion, to decrease the weight of the side sheets, and to lessen the wind 
resistance to the wheel when moving rapidly. In some steel wheels 
these holes are omitted; in others a larger number than the four 

shown here are used. Fig. 
499 gives a better idea of 
the general appearance of the 
wheel ready to use, being 
lettered the same as Fig. 498. 
The spokes shown in Fig. 499 
are painted on the smooth 
exterior of the plates, but in 
other wheels these spokes are 
formed in the plates as pre¬ 
viously mentioned. 

Steel Wheels Designed for 
Cushion Tires. Sheet-steel 
wheels, particularly those of 
very thin sheets, have a cer¬ 
tain amount of springiness, 
this being utilized with solid 
and cushion tires on the 

Fig. 499. Sheet-Steel Wheel Complete . • , 1 , , i ■, , 

assumption that the wheel 
will absorb the vibrations set up by the road inequalities. In Figs. 
500 and 501, a wheel is shown which was designed for this express 
purpose. 1 he wheel is called an elastic wheel and uses solid tires. 

By means of the figures the construction is made clear, the wheel 
consisting of two halves, one a single sheet of metal attached to the 
hub and forming its own rim portion, and the other a section which 
consists of two sheets, one attached to the hub and forming its own 
rim portion, with another additional plate riveted to it near its outer 



GASOLINE AUTOMOBILES 


635 



end and attached to a middle flange on the hub. The two outer 
members of themselves would be very springy and consequently 
very weak, being of very thin metal. The diagonal extra sheet stiffens 
the whole construction, besides adding 50 per cent to its side strength. 
This is also of thin metal, so the whole wheel retains some springiness. 

Parker Pressed=Steel Wheels. One fault with all the steel and 
sheet-steel wheels mentioned was that they did not resemble other 
wheels, consequently the people did not want them. Moreover, in 
many cases, their construction did not adapt them to the 
use of regular tires but, on the contrary, called for special 
and expensive forms. However, none of these drawbacks 
are present in a new form of pressed-steel wheel, Fig. 502. 
Upon close inspection it will be seen that this wheel has 
no felloe in the ordinary sense, the rim of the wheel form¬ 
ing the only felloe. In this respect, the wheel is an 
outgrowth of the former Healy demountable rim, the 


Fig. 500. Steel 
Wheel 


Fig. 501. Disassembled Steel Wheel 


modern form being a combination of a demountable rim with steel 
spokes. This wheel is suitable for any car, the hollow steel spokes hav¬ 
ing great sustaining power. It is interchangeable with all ordinary 
wood artillery wheels of the same size, and fits between the usual hub 
flanges. The spoke portion is made as a pair of units, each forming 
half of all the spokes, the two being welded together. When finished 
in this manner, they have half the weight and more than twice the 
strength of the wood wheel, the greatest saving being at the rim, 
by the removal of from 60 to 100 pounds of metal and wood. 

This wheel takes the ordinary demountable rim directly upon 
the ends of the spokes, the one shown being the No. 2, which is suit- 















636 


GASOLINE AUTOMOBILES 



able for about twelve different rims as made by the largest manu¬ 
facturers. The No. 1, whose only difference in appearance is a flat 
spot just under the bolt heads at the ends of the spokes, takes all one- 
piece clincher or straight side rims, whether clincher or Q.D. (quick 
detachable). The wheel shown is a 36- by 4|-inch size, made from 
.083-inch sheet steel, with ten spokes If inches round and a center 
portion, all of the same thickness of steel. 

A number of other pressed-steel wheels, made, like the Parker, 
by pressing out two or more simple units, and welding these together, 

are making their appear¬ 
ance. These show great 
ingenuity and variety in 
the methods used to pro¬ 
duce this same result and 
yet avoid the Parker 
patents. This form of 
wheel, having the appear¬ 
ance of wood, yet with 
greater strength and 
dependability and also of 
lighter weight, may per¬ 
haps be the final answer 
to the wheel problem; 
certainly this is possible 
if quantity production 
can bring them down 
below the price of wood wheels, which now seems apparent. 


Fig. 502. General Appearance of Parker Hydraulic 
Steel Wheel 


COMMERCIAL=CAR WHEELS 


Requisites. On commercial cars the service is so different as 
to call for entirely different wheels. Of course, many commercial- 
car wheels are nothing but pleasure-car wheels with heavier parts 


throughout, but it is coming to be recognized that heavy trucks, 
tractors, and similar vehicles should have their wheels designed for 
the service required of them the same as lighter cars. No springiness 
or resiliency is required for heavy truck service, but simply these 
three things: strength to carry load and overloads; strength to 
resist side stresses; and such material, design, and construction as 




GASOLINE AUTOMOBILES 


637 


will make for low first cost and low cost of maintenance. A fourth 
desirable quality might be added to these, the quality of being 
adaptable or adapted to the tires to be used. 

Wood Wheels. Taking Fig. 503 as an ordinary heavy vehicle 
wheel, let us see in what ways it fulfills or falls short of these require¬ 
ments. The spokes are large in both directions and widened out at 
the felloe to give greater side 
strength. The felloe, which 
cannot be seen, may be judged 
as to size from the width and 
location of the dual tires, 
which would indicate great 
-width and considerable thick¬ 
ness. This style of tire calls for 
a steel band shrunk over the 
felloe, while the heads of the 
cross-bolts show how the tires 
were put on and held on. 

All these make for great 
strength in both horizontal 
and vertical directions, and 
all parts except the spokes 
are simple to make, and even 
these are simple for the wheel 
manufacturer whose shop is 
rigged to make them. More¬ 
over, to fill the last require¬ 
ment, the wheel is adaptable to this tire or to any one of a number of 
motor-truck tires which might be used. 

A slight variation from this is the double-spoke wheel, in which 
the spokes, in addition to being placed in double rows, are set so 
as to miss each other across the wheel, that is, each spoke of one 
row coming between two of the other. This placing allows the spokes 
to be made larger and stronger than in the ordinary case, while the 
double rows have the same strengthening effect as the tapering of 
spokes. The hub portion is assembled as two separate wheels, so 
that the work of assembling as well as of making the parts is slightly 
more than with the ordinary wheel. This is more than compensated 



Fig. 503. Double-Tire Wood Truck Wheel 




638 


GASOLINE AUTOMOBILES 


for by the added strength. It is but fair to state that each of the 
last two wheels described is of English make. 

In all wood wheels, the blocks composing the wheel and tire 
are of well-seasoned rock elm, sawed into wedge-shaped blocks, with 
the fiber lengthwise. The blocks are glued and nailed together 
until they form a circle. They are then turned round and to size 
in a large wood lathe, a shoulder \ inch wide being formed at the 
same time on each side of the tire 2.5 inches from the tire surface. 
A heavy steel ring with a corresponding shoulder is then shrunk 



Fig. 504. White Cast-Steel Wheel 


over the wood shoulder on each side of the tire, drawing it together 
much like the ordinary steel tire on a wood wheel of a carriage. 
Bolts are run through these rings and through the wood blocks from 
side to side to prevent the blocks from splitting sidewise. To increase 
the life of this tire, steel wedges | inch thick are driven crosswise 
into the face of it 2.5 inches deep around the whole tire about 3 
inches apart. These wedges prevent the tire from slipping; in fact, 
they act like an anti-skid chain and do not harm the pavement, 
being set flush with the surface of the wood blocks. 











GASOLINE AUTOMOBILES 


639 


It is said that one set of these tires was used for nine months, 
and at the end of that time they were still good for service. The 
tires reach clear to the hub, thus doing away with spokes and enabling 
the tires to be slipped over the hub and held in place by a removable 
flange bolted through the wood to the fixed flange on the opposite 
side of the hub. 

Cast=Steel Wheels. The heavier the service the more unsuit¬ 
able do wood wheels become, that is, wood-spoke wheels. For many 
five-ton trucks, practically all seven- and ten-ton trucks, and nearly 
all tractors, the cast-steel wheel is used, either spoked or solid, the 
spoked form being given the preference. Fig. 504 illustrates a spoked 
cast-steel wheel, fitted with a solid tire. The wheel is cast with ten 
-heavy ribbed spokes, a ribbed felloe, and a grooved-felloe surface, 
into which the tire is set. 

Miscellaneous Wheel Types. Steel. Steel wheels are gaining 
for heavy truck use, and a number of the better steel-casting firms 
are now getting into this work, with the result that better steel 
wheels are becoming available. 

Other constructions, such as steel and wood combination wheels 
with removable and replaceable spokes, and the like, are rapidly 
going out of existence. Truck work is unusually severe, and it takes 
but a few weeks of actual use to show up any of the so-called freak 
wheels. The simplest seems to be the best, the only question at 
present being whether the material shall be wood or cast steel. 
Pressed steel may offer some opportunities in combination with 
welding, since good work has been done on pleasure-car wheels of 
this type. 

Spring Wheels ivith Longitudinal and Tangential Springs. Spring 
wheels for both pleasure cars and trucks have not proved to be all 
that was claimed for them. For pleasure-car use they have gone 
out entirely; for truck use they are restricted to the smaller and 
lighter sizes, as the 1J- and 2-ton sizes driven at high speeds in city 
work. On these sizes, one or two well-designed forms are giving 
good service. The cherished dream of putting the pneumatic tire 
out of business through the medium of the spring wheel is still a dream. 

When longitudinal springs are used to do away with the alter¬ 
nations of stresses peculiar to the radially disposed springs, the 
appearance of the wheel is much altered, as Fig. 505 shows. This 


640 


GASOLINE AUTOMOBILES 



wheel consists of an inner wheel, having its own spokes ten in 
number—and its own felloe. To the felloe are attached by means 
of bolts V-shaped arms, which hold one end of a series of spiral springs, 
the other end of each of the springs being held in a similar V-shaped 
arm bolted to the opposite side of the outer felloe carrying the tire. 
There are eighteen of these springs in two sets of nine each. Those 
springs which have their near end fastened to the near side of the 
inner felloe have the far end fastened to the far side of the outer 


felloe, while those attached to the far side of the inner felloe have 
the other point of attachment on the near side of the outer felloe. 

When the wheel strikes an obstacle, a twisting action is set up, 
the outer felloe and tire moving while the inner felloe and axle remain 
stationary. This twisting of the springs tends to coil them tighter, 
which results, when the obstacle is passed, in the springs untwisting 
and turning the outer felloe and tire backward as far as it was previ- 


Fig. 505. Seaton (American) Spring Wheel 


GASOLINE AUTOMOBILES 


641 


ously moved forward. Since, however, the springs have a certain 
amount of stiffness in their coils, and the wheels do not rise and fall 
relative to one another, except in so far as the twisting action is 
concerned, it follows that considerable shock must be transmitted 
to the axle and thus to the body and its occupants.* This wheel, 
therefore, while possessing strength to resist side stresses, does not 
give the smooth riding qualities so much desired. 

A wheel very similar in appearance and action but with the 
wood spokes eliminated has been used very extensively in the last 
few years by the express companies and other big users of motor 
trucks. Starting with a few of them on front wheels, they have 
saved tires and tire money 
to such an extent that 
the companies have added 
more and more. Next they 
were tried on rear wheels. 

Seeing the good results 
obtained by the big com¬ 
panies with these wheels, 
many smaller firms and 
tradesmen with only one 
or two trucks have adopted 
them. They take a small size 
solid tire in place of a very 
large pneumatic and are said 
to cut the tire cost from one- 
half up to two-thirds and more. While used mainly for vehicles carry¬ 
ing a 1-ton load, they have been tried successfully on 2-ton vehicles. 

It is in this class of service—the lighter vehicles for smaller firms 
—where every item of expense must be watched very carefully that 
the resilient wheel should show the best results. For heavy work, 
there seems little future for it. 

A form of wheel which comes somewhere between the two just 
mentioned, having some side strength and easy-riding qualities, while 
at the same time participating in part of the principles of both those 
described, is that shown in Fig. 506, which is a diagram showing the 
construction. This consists of spiral springs used not radially nor 
longitudinally, but tangentially. Moreover, the springs are not 



Fig. 506. Diagram of Action of Taylor Spring Wheel 





642 


GASOLINE AUTOMOBILES 


attached directly to the hub, but to levers pivoted on an outer, or 
false, hub. When an obstruction is met with, so that the tension of 
the springs is altered, the springs act upon the levers and thus turn 
the false hub about the real inner hub by an amount corresponding 
to the character of the obstruction. This eccentric motion of the 
outer hub, induced by the spring action, takes up the shock of 
the road obstruction much as does the wheel shown in Fig. 505. 

The construction is such as to allow of the springs being covered 
by means of a water-tight case, which will protect them from the 
elements and thus lengthen their life. This is a good feature which 
is lacking in all other wheels thus far shown. 

Spring Wheels with Flat Spiral Springs. The flat spring bent 
into a semicircular or spiral form is little used for spring wheels. 
There is a double reason for this; they lack every desired quality, 
unless it be side strength. If stiff enough to handle considerable 
load, they are heavy, they are slow acting, and their action is long 
continued; if made light, they act too much and the vibrations are 
long drawn out. Moreover, if few springs are used, the breaking 
of a single one puts the wheel out of use; if many are used, the wheel 
becomes very heavy. 

While a number of flat-steel spring wheels have been constructed 
both here and abroad, they have not been uniformly successful, as has 
been pointed out. A French form which was widely tried a few years 
ago had a pair of sets, each of six springs, with a long curving shape, 
one end attached to the hub and the other to the rim, while the leaves 
on the two sides were set in opposite directions. The idea was that 
loading would produce an eccentric movement of the rim relative 
to the hub, and that the opposing of the two sets of leaves would 
produce an absorption, one side absorbing the tendency to movement 
of the other. In practice, however, this idea did not work out, as it 
gave a noisy, hard-riding wheel, with a tendency for the springs to 
break. These disadvantages, added to its weight, put a stop to its use. 

An American device, constructed along somewhat similar lines, 
but with all springs pointed in one direction, had only a limited use 
in the home town of the inventor and is not now used. 

Modern Status of Spring Wheel. The more modern view is not 
that the solid tire will be eliminated, but that a form of steel-spring 
or other resilient wheel will be produced which will have all the advan- 


GASOLINE AUTOMOBILES 


643 


tages of wood and, in addition, will so save the solid rubber tires that 
mileages twice as great will be obtained. In this way, the tire cost 
will be cut in half, which will be sufficient within the ten-year life of 
the ordinary commercial car to warrant the purchase of the more 
expensive wheels. 

In the use of spring wheels, as well as of wire wheels for pleasure 
cars, the tire and rim situations are closely inter-woven. No special 
form of wheel or rim can be successful which calls for a special tire in 
addition, because, in case of trouble on the road, in a small town, or 
anywhere outside of the big cities with large and varied sources of 
supply, the users would not be able to replace the tire. As will be 
pointed out later, the present rim-and-felloe situation, which might be 
described as chaotic, must necessarily continue until the tire situation 
is cleared up. That done—and it is now in a fair way of being done 
soon—the rim situation also will be quickly cleared up, and, following, 
that of the wheel felloes. The natural fitness of the various forms and 
the unfitness of others to meet popular demand is rapidly clearing the 
way for the engineers and manufacturers who are attempting this 
standardization work. 

WHEEL TROUBLES AND REPAIRS 

The removal and handling of wheels present probably the 
biggest problems in connection with them. True, broken wheels 
give the repair man a good deal to think about, but the quick accu¬ 
rate handling of jobs in which a broken wheel figures depends more 
upon possessing and knowing how to use certain equipment than 
anything else; the operations are so simple that they require no 
particular skill or knowledge. 

Wheel Pullers. In handling wheels a wheel puller of some form 
is generally a necessity; wheels are removed so seldom that they are 
likely to stick, and they get so much water and road dirt that there 
is good reason for expecting them to stick or to be rusted on. This 
means the application of force to remove the wheel. For this purpose, 
a wheel puller is needed, and a number of these have been illustrated 
and described previously, as gear pullers, steering-wheel pullers, 
etc. Any one of these devices which is large enough to grasp the spokes 
of the wheel and pull the latter outward and, at the same time, press 
firmly against the protruding axle shaft will do the work well. 



644 


GASOLINE AUTOMOBILES 



Fig. 507. 


Makeshift Wheel Puller for Road 
Repair Work 


Sometimes, however, while owning a puller, a wheel breaks 
down on the road where this is not available, or the repair man is 
called without being told the trouble, so that he does not bring the 

puller with him. In such cases, 
the repair man must improvise 
some kind of a puller out of what 
he has on hand. Everyone carries 
a jack, so it is safe to assume that 
one of these wall be available as 
well as some form of chain. If a 
chain of large size is not available, 
tire chains—particularly extra 
cross-links—may be fastened to¬ 
gether to answer the purpose. If 
chain is lacking, strong wire, wire 
cable, or, in a pinch, stout rope 
can be substituted. Attach the 
rope, wire, or chain to a pair of 
opposite spokes of the wheel, 
Fig. 507, allowing usually about two feet of slack. Draw the chain 
out as tightly as possible, place the jack with its base against the 
end of the axle and work the head out by means of the lever until it 

comes against the chain. 
£^jrnuc.Ttwheeis -_— Then by continued but 

careful working of the 
jack, the wheel is pulled 
off the axle. 

If rope, wire, or wire 
cable is used, it is advis¬ 
able to place a heavy 
piece of cloth, burlap, or 
something similar over the 
head of the jack to pre¬ 
vent its edges cutting 
through this material. 
With rope only enough slack must be used to allow the jack in its 
lowest position to be forced under it; this must be done because there 
is so much stretch to the rope itself and so little movement in 


O 0 

o o 


*— n- 



o o 

o o 



> 







o o 





o o 

1 

1 






-2 


} 



o o 


“_I ™~[]r 


<£ Truck Wheels-^ 

4'-o" 





Fig. 508. 


Tire Platform or “Dolly” for Handling 
Truck Wheels 





































































































GASOLINE AUTOMOBILES 


645 


the ordinary jack, that the combination of rope and jack does not 
always work to advantage. 

Similarly, the handling of heavy truck wheels gives much 
trouble even in the garage, for they are so big, heavy, and 
bulky that ordinarily two men are needed. One man can do 
the trick, however, with a platform or “dolly” like that shown 
in Fig. 508. This consists of a platform about 4 feet long by 
25 inches wide, fitted with casters at the four corners. Inside of the 
central part are placed a pair of wedges, one of which can be moved in 
or out by means of a crank handle. To use this, the wheel is jacked up 
a little over 2 inches, and the truck pushed under. Then the movable 
wedge is forced in against the tire so that the two wedges hold the 
wheel firmly and carry all of its weight. Then the casters are turned 
at right angles so that the platform and the wheel may be moved off 
together. The truck wheel is removed in the usual manner, that is, 
with the aid of the wheel puller or such other means as the garage 
equipment affords. The dolly also forms a convenient means of 
handling the wheel when it is put back on its axle. 

TIRES 

Kinds of Tires. Broadly, there are three general classes of tires: 
the solid, the pneumatic, and the combination or cushion. The solid 
tire needs little comment or discussion here—being solely for com¬ 
mercial cars—except in so far as it is used with some form of spring 
wheel, hub, or rim, as just described. Similarly, the cushion tire is 
mostly used for electric cars, its use following that of the solid tire. 

PNEUMATIC TIRES 

The pneumatic tire was originally developed for bicycle use and 
in the beginning many single-tube tires were used. All of the tires 
used today have two parts—an inner and an outer tube. 

Classification. Considering only the double-tube types, there¬ 
fore, the pneumatic tire may be divided into three kinds: the Dunlop; 
the clincher; and various later forms brought out to go with the detach¬ 
able demountable rims; and similar devices. These latter vary 
widely in themselves, but all are modifications of the clincher form, 
with minor differences of the difference in rims. 

Dunlop. The Dunlop tire, so named after the Irish physician 
who invented and constructed the first pneumatic tire, is brought 






646 


GASOLINE AUTOMOBILES 


down to meet the rim in two straight portions, perfectly plain and of 
even thickness, that is to say, the tire has no bead, as it is now 
called. The tire fabric is brought down to a straight edge at the rim, 
as well as the rubber covering, as shown in Fig. 509. A is the steel 
rim of the wheel, B the inner tube, C the outer shoe, which at the 
rim or inner portion is brought down to the two straight parts DD. 

This tire, like all of the early tires, had to be put on over the 
edge of the rim by sheer strength, coupled with the flexibility of 
the tire when not inflated. This was a hard task, and, moreover, 
as soon as the tire was punctured or otherwise deflated, there was 
a strong possibility of its being thrown off, and possibly lost, at 
east after it had been stretched on and off the rim a few times. 



Fig. 509. Section of 
Dunlop Tire 



Fig. 510. Section of Typical 
Clincher Tire 


Clincher. To prevent this latter happening, the clincher rim 
and tire were brought out, each being dependent upon the other. 
In the clincher tire, the fabric is brought down to the rim, and then, 
instead of being left straight out as in the Dunlop, the material is 
formed into a hump, or bead, which is shaped just like the hollow 
formed in the rim. The latter differs from the usual Dunlop rim 
only in having this deep depression to fit the bead of the tire. Fig. 
510 shows this, in which the parts are lettered as before. In both 
cases, the fabric of the tire is sketched in, and it may be noted that 
the layers are fewer in number in the older form. 

The great majority of tires now in use are of this type, although, 
like the original Dunlop, it must be forced on and off the rim by 
the stretch of the deflated tire, and by sheer strength, coupled in this 
case with considerable natural ingenuity and some tools for lifting 














GASOLINE AUTOMOBILES 


647 


the hard non-stretchable beading over the edge of the rim at one 
point. This done, the rest is easy. For this purpose many tools 
have been bought; some good, some bad, and some indifferent. After 
a fashion, all do the work, but that tool is best which performs 
the operation most easily, most quickly, and with the least damage to 
the tire or rim. Fig. 511 shows a useful tool for this purpose. 

The wire wheel and demountable rims, both allow quick road 
changes of damaged tires, leaving the work of tire repair to be done 
at home in the garage with proper heat, light, tools, and materials. 
Phis is rapidly bringing back into use the lower price clincher and 
straight-side tire forms, also many new tools have made their 



Fig. 511. Tire Removing Tool 


removal or attachment a much easier and more simple task. 

- Demountable Rim Types. Following the development of the 
clincher tire and rim until this form of tire was practically universal, 
came the first forms of the 
demountable rims, which 
consisted of a detachable 
edge or rim portion, like the 
edge of the clincher rim in 
section. These were locked 
in place in various ways in 
the different forms, but the 
first demountable rims—they 
were called detachable rims 
—were made by cutting the clincher rims into two parts, one of them 
detachable. This allowed of slipping the tire on over the rim in a 
sidewise direction, and did away with the stretching and pulling 
necessary with the plain clincher. Since this was a tire which was 
detachable more quickly than the ordinary tire, it was given the name 
“Quick Detachable”, and now both parts are known to the trade as 
the Q.D. tire and rim. 

Non-Skid Treads. All of the later developments in the clincher 
tire have been along the line of studded or formed treads to prevent 
skidding. In this many different things have been tried. Fig. 512 
shows sections of many of the representative tires on the market. 
They are well known, and only the last three need any comment. 

Fig. 512 H shows the Kempshall (English) tire tread, which is 
built up of a series of circular button-shaped depressions, or cups, 









648 


GASOLINE AUTOMOBILES 


which hold the pavement by means of the suction set up when they 
are firmly rolled down upon it. This tire has been very successful 
in England, but as yet has not been used much in this country. 

The Dayton Airless tire, shown in Fig. 512 /, is a bridge- 
constructed cushion tire in which the usual air space is given over 
to a series of stiffening radial pieces of solid rubber, these with the 
tread forming the bridge or truss. Fig. 512 J shows the Woodworth 
adjustable tread for converting the usual smooth-tread tires of 
whatever shape or form into non-skids. It is a leather and canvas 



Fig. 512. Various Types of Non-Skid Tire Treads 


built-up structure, shaped like the exterior of a tire, and freely 
studded with steel rivets. When in place, the tire has all of the 
appearance of a leather-tread tire with steel studs. 

Proper Tire Inflation Pressures. With the recent great increase 
in the value of rubber and the price of tires, the advice of manu¬ 
facturers on the subject of tire wear is of great and growing impor¬ 
tance. Nearly every manufacturer of tires is now recommending 
a table of inflation pressures which agree among themselves more 
or less closely. In each and every case, however, the makers are 





















GASOLINE AUTOMOBILES 


649 


advising higher pressures than those generally used, stating that 
the people do not pump their tires up hard enough to get the best 
results from the materials in the tires. There should really be no 
conflict of interests here as the owner should be as anxious to get his 
mileage out of the tires as the makers are to make good their 
guarantees. 

Many makers have stated, as a result of their years of experience, 
that more tires wholly or partially fail or wear out from under¬ 
inflation than from any other one cause. It thus behooves the 
owner of a car to look well to the pressure in his tires, not occasionally 
but very frequently. As the majority of gages attached to pumps 
in public garages are seriously in error, each motorist is advised to 
purchase his own gage—one of the pocket type which is simple and 
inexpensive—and carry it with him at all times. 

In some cases, it will be found that pumping the tires up to the 
makers’ specified pressure will result in unusually hard riding, and 
the motorist must be his own judge as to whether he wants to ride 
more comfortably and get less wear out of his tires or to put up with 
the discomfort and get every cent of wear out of them. In this 
matter, very few will choose the latter course. 

Use of Standard Pressure and Oversize Tires. There is really a 
different way out. If the tire pressure advised by the maker results 
in too hard riding for comfort while comfortable pressures result in 
too much wear, the motorist is advised to get large size tires. These 
on the same car will have a greater carrying capacity than the weight 
of the car by a large margin. Just in the proportion of the tire 
capacity to the weight of the car will be the pressure recommended 
to the pressure utilized. 

A simple example will make this clear: Suppose, for instance, 
a car weighing 3850 pounds, equipped with 34- by 4-inch tires, for 
which the makers claim a carrying capacity of 1100 pounds per wheel 
and recommend a pressure of 95 pounds. If this pressure be too high 
for comfort, and lower pressures, say 80 or 85 pounds, result in too 
rapid wear, the motorist should use larger tires. For instance, a 
34- by 4|-inch tire is scheduled to carry 1300 pounds per tire, and the 
pressure recommended is 100 pounds. The car weight per tire is 
962 pounds, say 970. Changing to the larger tire gives a capacity 
of 1300 pounds per wheel, while the load is actually but 970. This 




650 


GASOLINE AUTOMOBILES 


change provides a surplus capacity which can be utilized to increase 
comfort. 

Hence, if the tire be pumped up in the ratio of the carrying 
capacity of the tires to the actual weight carried, the spirit of the 
manufacturers’ instructions will have been followed, comfort assured, 
and long life of the tire attained as well. Here the ratio of the 
capacity to the weight is as 1300 :970. If now the pressure be figured 
from this, using the 100 pounds recommended, a suitable pressure 
will be obtained. Thus 

1300 : 970 : : 100 : x 
x =74.6 pounds 

The pressure, therefore, in round numbers will be 75 pounds, and 
if this or any comfortable pressure above this be used, only the 
proper amount of tire wear will result, and a comfortable riding car 
will be assured. 

However, this proposition, namely, changing from 34- by 4-inch 
to 34- by 4^-inch tires, is one which calls for entirely new rims, and 
possibly entirely new wheels, or at least new felloes, because the bottom 
diameter of the 34- by 4|-inch is different from that of the 34- by 
4-inch. In such a case as this, the motorist would gain by changing 
to a still larger size, say 35- by 4|-inch, which change can be made 
without disturbing the old rims, as the 35- by 4|-inch is an oversize 
for 34- by 4-inch. This size also is recommended to carry 1300 
pounds at 100 pounds pressure per square inch, but maximum pleasure 
and comfort will be obtained from it at between 72 and 80 pounds. 

In general, the rule for oversize tires is this: Oversize tires are 
1 inch larger in exterior diameter and J inch greater in cross-section 
than the regular sizes, and any tire so sized will fit interchangeably 
with the regular size on the same rim. In general, too, the even-inch 
sizes, as 30, 32, 34, etc., are considered as the regular sizes, while the 
odd-inch sizes, as 31, 33, 35, etc., are considered as oversizes. The 
above is for American or inch sizes only. The foreign, or millimeter, 
tire and rim situation is in an even worse condition, and changes of 
sizes are difficult in all cases and impossible in most. 

Changing Tires. In the matter of changing tires, care must be 
exercised in selecting the new tire of such a size as will fit the old 
rim. A larger section of tire of the same nominal outside, or wheel, 
diameter would call for a smaller rim diameter, meaning a change in 


GASOLINE AUTOMOBILES 


651 


rims and possibly wheels. A larger nominal outside diameter will 
change the speed of the car and, if great, may be too much for the 
engine, calling for new gearing as well. The following tabular 
matter will be of interest, as it gives the changes in the metric 
size tires which can be made without altering either wheel or rim 
or changing the gearing. 


Possible Tire Changes 


760 

mm. 

X 

90 mm. wheels can be altered to. 

.... 765 mm. 

X 

105 mm. 

810 

mm. 

X 

90 mm. wheels can be altered to. 

. . . .815 mm. 

X 

105 mm. 




. 

and 820 mm. 

X 

120 mm. 

840 

mm. 

X 

90 mm. wheels can be altered to. 

.... 850 mm. 

X 

120 mm. 

870 

mm. 

X 

90 mm. wheels can be altered to. 


X 

105 mm. 

\ 




or 880 mm. 

*X 

120 mm. 

910 

mm. 

X 

90 mm. wheels can be altered to. 

.... 915 mm. 

X 

105 mm. 





or 920 mm. 

X 

120 mm. 

815 

mm. 

X 

105 mm. wheels can be altered to. 

.... 820 mm. 

X 

120 mm. 

875 

mm. 

X 

105 mm. wheels can be altered to. 

.... 880 mm. 

X 

120 mm. 





or 895 mm. 

X 

135 mm. 

915 

mm. 

X 

105 mm. wheels can be altered to. 

.... 920 mm. 

X 

120 mm. 





or 935 mm. 

X 

135 mm. 

880 

mm. 

X 

120 mm. wheels can be altered to. 

.... 895 mm. 

X 

135 mm. 

920 

mm. 

X 

120 mm. wheels can be altered to. 

.... 935 mm. 

X 

135 mm. 


These can be used without changing the gearing or the wheels, 
but to use different tires without changing rims is another matter. 
It will, therefore, be necessary to have another table of the various 
tires which are interchangeable on the same rim. Of the makes 
which are fairly international in character may be mentioned the 
German “Michelin” and the French “Continental”. The following 
Michelin tires may be fitted to the same rim, the two tires on the 
same horizontal line being interchangeable in each case: 

Interchangeable Michelin Tires 

650 mm. X 65 mm. and 700 mm. X 75 mm. 

700 mm. X 65 mm. and 750 mm. X 75 mm. 

750 mm. X 65 mm. and 800 mm. X 75 mm. 

800 mm. X 65 mm. and 850 mm. X 75 mm. 

700 mm. X 85 mm. and 710 mm. X 90 mm. 

750 mm. X 85 mm. and 760 mm. X 90 mm. 

800 mm. X 85 mm. and 810 mm. X 90 mm. 

860 mm. X 85 mm. and 870 mm. X 90 mm. 

The following tires of the Continental make are interchangeable 
on the same rims: 












GASOLINE AUTOMOBILES 


652 

Interchangeable Continental Tires 

750 X 75 (motor cycle) and 750 X 80 (voiturette) 

750 X 65 (motor cycle) and 750 X 65 (voiturette) 

800 X 75 (motor cycle) and 800 X 75 (voiturette) 

700 X 85 and 710 X 90 (light and heavy) 

750 X 85 and 750 X 90 (light and heavy) 

760 X 90 and 700 X 100 (light and heavy) 

870 X 90 and 810 X 100 (light and heavy) 

910 X 90 and 910 X 100 

820 X 100 and 820 X 125 

880 X 120 and 880 X 125 

920 X 120 and 920 X 125 

815 X 105 fit only 105 mm. rims 

Note. Although the 105 mm. tire requires a special rim, a 90 or 100 mm. 
cover can also be fitted on the same rim in the case of necessity. 

810 X 90 or 810 X 100 fit on the 105 mm. rim 

875 X 105 fit on the 105 mm. rim 

910 X 90 or 910 X 100 fit on the 100 mm. rim 

895 X 135, 935 X 135, and 1000 X 150 require their own special rims 

Speed Changes Due to Changed Tires. Before leaving the subject, 
it might be well to say a few words concerning the change of speed 
which a change in tire sizes will make in a vehicle, this in some cases 
being so serious as to impair the utility of an engine formerly found 
to be right in every particular. In the course of a very wide experi¬ 
ence, the writer has found this to be the case with many old cars. 
Losing the old small wheels and tires, the engine was able to negotiate 
all grades easily and make the required speed at all times. With 
a change to larger wheels and tires, the car ran faster at all times 
and gave much more trouble generally. It also proved a poor hill 
climber, so much so, in fact, that the owner had to go one step further 
and change the gearing so as to give the old speed ratios before the 
engine again acted satisfactorily. 

Recent Tire Improvements. There have been but three recent 
notable improvements in tires which are briefly discussed. 

Tire Valves. There have been several kinds of troubles with 
the old form of tire valve. It was spring actuated, and the springs 
were so small as to cause much trouble; further, it had to be screwed 
in place, requiring a special tool. There are several new valve forms 
with more than one seat, and others with an improved seat designed 
to screw in with the fingers and to offer little or no resistance to 
inflation. 



GASOLINE AUTOMOBILES 


653 


Inner Tubes. Improvement has been made in inner tubes 
by the use of better and purer rubber in much thicker sections. 
Some of these have a partial fabric reinforcement; others are made 
and then turned inside out so that the tread portion is under com¬ 
pression, thus resisting punctures or internal pressure. Other 
designs present a tube larger than the inside of the tire before infla¬ 
tion; this produces a truss formation of the rubber, which the air 
pressure stiffens. 

Cord Tires. The real improvement of value, however, is the 
cord tire. One form of this is shown in partial section in Fig. 513. 
This shows graphically that the difference between this tire and 



Fig. 513. Section of Goodrich Silvertown Cord Tire, Showing Inner Construction 


other forms is that the 4 to 6 or more layers of fabric have been 
replaced by two layers of diagonally woven cord. This cord is 
continuous, rubber impregnated, rubber covered, and, through its 
size, allows a great and very even tension. Lessening the amount 
and thickness of the fabric has given a greater percentage of rubber 
in the tire; consequently, the cord tire is more resilient. The advan¬ 
tages claimed for it are: less power used in tire friction, which means 
more power available for speed and hill climbing; greater carrying 
capacity in same size; saving of fuel; greater mileage per gallon of 
fuel; additional speed; quicker starting; easier steering, thus less 
driving fatigue; greater coasting ability; increased strength; and 
practical immunity from stone bruises owing to superior resiliency. 





654 


GASOLINE AUTOMOBILES 


RIMS 

Kinds of Rims. Nearly all rims are of steel or iron, but vary 
greatly as to types. The writer has therefore chosen only a few 
of the well-known ones, no preference being shown in this. 

Rims will be taken up in the order of their development. Natu¬ 
rally, the first rims were of the plain type, while the latest are of the 
demountable, remountable, or removable types, all these being very 
much the same. Between the two came the clincher rim, which is 
properly a plain rim; and the quick-detachable rim. 

Plain Rims. The form of rim first used was naturally the solid 
type, shown with the Dunlop tire in Fig. 509. This form is a simple 
endless band with two edges just high enough to prevent the tire 
from coming off sidewise when it has once been stretched in place. 
Nothing like it is used today, the nearest approach being the form 
of rim used with single-tube bicycle tires. 

Clincher Rims. Clincher rims were brought out primarily to 
avoid the weaknesses of the Dunlop, viz, a weakness at the base, 
and, hence, it had an unusually heavy bead. Another fault which 
this tire remedied was the tendency under high pressure for the tire 
to draw away from the rim. This was avoided by the edge of the 
clincher being made fairly wide where it was designed to go into 
the pocket, or groove, formed by the contour of the rim. 

It is the depth of this pocket, or groove, and the corresponding 
size of the edge of the bead on the tire, both excellent qualities, which 
make the tire hard to put on and take off. This may be seen from 
the previous illustrations of clincher tires, notably Fig. 510. 

Quick=Detachable Tire Rims. It was this inherent difficulty 
of handling the clincher tire and rim which brought about the quick- 
detachable tire. This did not differ from the clincher tire in the 
tire portion, the difference being in the rim, which has one curved 
portion made in removable form, with a locking ring outside of it or 
made integral with it. In some quick detachables, the rim is expanded 
by a special tool and a spacing piece set into place, which holds the 
edge expanded. When this is done, the ring—as it is a simple ring 
with special ends—is held in place until released by the use of the 
special tool. On the end of the ring there are two little square lugs 
which project downward and have a hook shape. The one edge of 
the rim, made flat and straight on that side, has a slot with stag- 


GASOLINE AUTOMOBILES 


655 


gered, rectangular ends into which these lugs fit. It requires force 
to spring the rings together so the lugs will go into the slots, but once 
in place, the natural springiness of the rings holds them firmly in 
place, and holds the tire as well. 

Figs. 514, 515, and 516 are given to show how this ring is put 
in place on a tire. Fig-. 514 shows the beginning of the operation, 
and the instructions for the different steps will make them clear. 
Thus: 

Always start with left end of the ring. Lock this in the rim as shown in 
Fig. 514, so that the end of the ring is flush with the slot provided for the second 
end. A dowel pin is provided to register the ring in the proper place. This must 
always be correctly centered or the ring cannot be applied. This done, the balance 
of the ring can be forced over the flange of the rim, as shown in Fig. 515, with the 
exception of the locking end. By means of the tool, the last locking end can be 



raised and forced over the rim into the recess provided for holding the same in posi¬ 
tion preparatory to drawing the ends together, Fig. 516, showing the correct 
position of the tool. 

Then by entering the two points of the tool in the holes provided in the 
ring, the ends may be drawn together, as shown in Fig. 516, and, with a slight 
additional leverage, the ends of the rings can be made flush. 

Before proceeding further, it should be stated that the object of 
the quick-detachable rim is the quick removal of the tire, in order 
to allow a quick repair or substitution of the inner tube. On the 
other hand, the object of the demountable, remountable, removable, 
and other rims is the removal with the tire of the rim itself to allow 


Fig. 514. Putting on a Q.D. Tire. 
The Start 


Fig. 515. Putting on a Q.D. Tire. 
Forcing Flange over Rim 



656 


GASOLINE AUTOMOBILES 




Fig. 516. Putting on a Q.D. Tire. 
The Locking Ring 


the substitution of a new tire and rim, the tire being already inflated 
and ready for use as soon as applied. The object of the removable 

wheel is the removal of the entire 
wheel with rim and tire in order to 
substitute a spare wheel with already 
inflated tire. 

It might be thought that these 
methods called for the carrying of extra 
weight, but the amount added is 
actually very small, as, by their use, 
tire tools and pump are dispensed with 
and their weight saved. 

Fig. 517 shows the former Good¬ 
year rim. This rim, as will be noted, is of the quick-detachable type, 
the idea being to remove the tire only. The rim itself has a button¬ 
hook shape with a slight ridge, or projection, answering to the handle. 
This is on the fixed side, the inner flange inside of the tire butting 
against it as a stop. The tire is pushed over against this, being held 

on the outside by a second 
flange of similar shape. The 
latter, in turn, is fixed in 
place by a locking ring, a 
simple split circular ring of 
deep oval section. This fits 
into the button-hook portion, 
its contour being such as to 
fit it exactly. In use, it is 
sprung into place, the outer 
edge of the hook on the rim 
and the natural spring of the 
ring preventing it from com¬ 
ing out. This makes a very 
simple and serviceable quick- 
detachable rim. To make 
doubly certain that the lock- 

Fig. 517. Former Goodyear Universal Rim ing ring cannot j ump out> a 

spreader plate is attached to the valve stem; screwing this down 
into place wedges the bead of the tire over against the outer flange, 




GASOLINE AUTOMOBILES 


657 



which, in turn, pushes the locking ring tight against the outer 
curved part of the hooked rim. When in this locked position, 
the upper part of the flange 
hangs over the locking ring, 
so that it cannot rise vertically, 
the only manner in which it 
could come off. This rim is 

, . . . i i i • • Fig. 518. Adapting Goodyear Rim to 

shown with a detachable tire in Clincher Tires 

position, but may be used with any standard clincher tire by the use 
of extra clincher flanges. Fig. 518 shows the rim with a set of these 
flanges in position, ready to take a standard clincher tire. 



Fig. 519. Universal Q.D. Rim No. 2 Arranged for Clincher and Dunlop Tires 


Quick-Detachable Number 2. Figs. 519 and 520 show the 
standard quick-detachable rim, now known as No. 2. This was 
adopted by the Association of Licensed Automobile Manufacturers 



Fig. 520. Universal Q.D. Rim with Tires in Place 


as a standard and given the above name. It has the feature of 
accommodating all regular clincher, or Dunlop tires. In Fig. 519, it 
is shown at A ready for a clincher tire and at B ready for a Dunlop 
tire, the adaptation for the straight sides being shown. 

The two parts of Fig. 520 show sections of tires in place, making 
clear the exact use of this reversible flange. A shows a regular 
clincher tire in place, while B reveals the reversed flange in place with 
a Dunlop tire. Both Figs. 519 and 520 show the construction of 



















658 


GASOLINE AUTOMOBILES 


the device, the outer dropped portion of the rim having a hole through 
it. The locking ring is split vertically and one end, just at the split, 

carries a projection or dowel pin 
extending downward. To put the 
rim on, this dowel pin must be 
fitted into the hole in the rim to 
give a starting place. When this 
has been done, one may force the 
balance of the ring into place 
around the wheel with any suit¬ 
able, thin, wedge-shaped tool./ 
The shape of this locking 
ring with a right-angled groove in 
its inner edge permits the outer 
flange to overlap it, which insures 
the retention of the ring when 
once it has been put in place. Furthermore, it gives the outer side 
flange a wider seat on the rim, thus making it more stable and longer 
wearing. 

As will be noted, the difference between these two rims—that is, 
the old Goodyear and the Universal No. 2—lies in the saving of one 
ring and the shape of the locking ring. Both of these are called 
universal rims because they may be used interchangeably for straight- 


Fig. 522. Latch Used for Locking Single Combination Ring which Replaces 
Former Side Ring and Locking Ring 

side and clincher types of tire. Other Q. D. Universals are shown in 
Fig. 521, although, in the opinion of tire men, the Universal form is 
slowly going out of use. 

To explain these briefly, No. 1 is a modification of the Goodyear,, 
with different shaped inner rings, while the locking ring and the lip 
formed in the felloe band to receive it are similar to those of Univer¬ 
sal No. 2. In 2 the only difference from 1 lies in the locking ring,. 





’y^Myyyyyyyyyyyyyy /////////a 




yyyyyyyyyyyyyy/yyyyyyyyyyy/yyyy^. 





zzTyyyyyyyyyyyyyyyyyyyyyyy/T^, 


Fig. 521. Sections through Three Popular 
Q.D. Universal Rims 





































GASOLINE AUTOMOBILES 


659 


which has a modified Z-section, with a lip extending over the outer 
edge of the felloe band. The third section differs from the other two 
only in having the outer ring and locking ring combined into one, and 
the felloe band changed to suit this. This combination ring is held in 
place by means of a simple swinging latch, which is shown open and 
closed in Fig. 522. When opened, this permits raising the end of the 
ring, to which the shape of the felloe band offers no resistance. The 
whole inner ring is taken off, following around the circumference of 
the wheel, after which the tire is easily removed. 

Quick-Detachable Clincher Forms. To return to the plain 
clincher tire and the Q. D. rim, which allows of its ready removal, 






Fig. 523. Popular Forms of Q.D. Clincher 
Rims, Shown in Sections 





Fig. 524. Three of the Most Widely Used 
Straight Side Q.D. Rims 


Fig. 523 shows four of the most prominent forms, these being indi¬ 
cated simply as flat sections of the rim, for the tue is the same in 
all cases. All these have the simple clincher edge on one side, with 
removable ring and locking device on the other. I hat at 1 has the 
same locking device shown at 2 in Fig. 521, the Z-shaped nng extend¬ 
ing over the edge of the band. That at 2 is practically the same as 
3 in Fig. 521. The one seen at 3 is similar to that at 2 except for the 
detailed shape of the ring as well as the lock (not shown). The 
advantage of the form shown at 4 is that the outer ring is self-locking, 
that is, the shape of ring and band are such that when the former 



















660 


GASOLINE AUTOMOBILES 


is in place the tire itself locks it. Its only disadvantage is that 
it is harder to operate than the other forms, yet despite this fact it 
has been recommended for general adoption as the only Q.D. clincher 
rim worth continuing. 

Q.D. Type for Straight Sides. To close the subject of straight 
side tires, the rims of the quick-detachable form now in use aside 
from those already shown are seen in Fig. 524. Here these are seen 
to be identical with 1, 2, and £ of Fig. 523, except that the fixed 
side is arranged for a straight side instead of being made with a clinch. 
Here again, the last form of self-locking type has been recommended 
as a standard. 

Demountable Rims. All, or practically all, demountable rims 
come under one of two headings—those in which the tire can be 
detached on the wheel without demounting (if it is so desired) and 



those which are of the transversely split type and must be demounted 
before the tire can be removed. In addition, there is a second division 
of demountable rims into those which have a local-wedge form of 
attachment and those which have a continuous holding ring, this, in 
turn, being held by means of local wedges. Any of the plain demount- 
ables, which will be called demountables from now on, may be of 
either type of attachment, as is also the case with the first-named or 
demountable detachables. 

Local Wedge Type. In the so-called local wedge type, which 
includes the well-known Continental forms (notably Standard 
Universal Demountable No. 3 and Stanweld No. 22 and No. 30), 
Michelin, Empire, Baker, Detroit, Prudden, Standard Universal 
Demountables No. 1 (formerly the Marsh), and No. 2, and others, 
loosening the six (or eight, as the case may be) bolts frees the rim 
directly without further work. In some of these, such as the Michelin; 
the various Continentals, including Stanweld No. 22 and No. 30; 













GASOLINE AUTOMOBILES 


661 





Detroit; Baker; and others, the wedges carry a projecving lip, which 
makes it necessary to unscrew the nuts far enough to allow the 
removal of the wedge so as to 
pick this lip out from under 
the tire-carrying rim. In 
others, such as Empire, S.U. 

No. 1 and No. 2, the con¬ 
struction of the wedge and 
rim is such that loosening 
them frees the rim, the upper 
part of the wedge or clip 
swinging down to the bottom 
position as soon as loosened, 
because of its heavier weight 
and the fact that there is no 
projecting edge to prevent it. 

While this latter construction 
makes a faster operating rim, 
it is an open question as to 
whether it is as safe as the 
other form. These two con¬ 
structions are shown very 
plainly in Fig. 525, in which 
A is the Michelin with lipped 
wedges, and B the Empire 
with plain wedges. 

In Fig. 526 is shown a 
pair of additional demount- 
ables, which are held by 
the local wedge method, the 
difference here being in the 
form of a wedge. Note that 1 
has a solid clincher rim and 
2 a straight side rim. The 
base, however, is the same 
for both and, as will be seen 
by examining this, has two 
curves in its upper surface, the straight side rim fitting into the lower 


Fig. 526. Two Popular Demountable Rim Forms 
—for Clincher Tires above, for Straight Side below 


Fig. 527. Sectional Drawing Showing Con¬ 
struction of Baker Demountable Rim 






























































































662 


GASOLINE AUTOMOBILES 




or bottom one, while the clincher form of rim fits into the upper one. 
Note, also, that the wedges are the same for these two. This makes 

the demountable parts 
of the rim practically 
universal in that the 
owner can change from 
clincher to straight side 
or vice versa by simply 
purchasing the extra set 
of tire-carrying rims, 
no change in the wheels 
or means of attachment 
being necessary. For 
this reason, the felloe 
band shown under these 
two rims has been sug- 


Fig. 528. The First Operation in Removing 
Demountable—Loosening the Bolts 

Process of Changing Baker Local Wedge Type. In Fig. 527 is 
shown the Baker, which, as mentioned previously, is of the local 

wedge type of demount¬ 
able, having a trans¬ 
versely split rim which 
must be removed from 
the wheel before the tire 
can be taken off. Per¬ 
haps this whole action 
will be shown more 
clearly by the progres¬ 
sive series of views, Figs. 
528 to 538, which show 
the various steps in re¬ 
moving and replacing a 
tire and tube mounted on 
a Baker rim, the same as 
is shown in section in 
Fig. 526. First, all the wedge bolts except the two nearest the valve 
stem, one on either side, are loosened by means of the special brace 


Fig. 529. Second Baker Demounting Operation— 
Jacking the Wheel and Starting to Pry off Rim 


gested as a standard for 
demountables. 












GASOLINE AUTOMOBILES 


663 




Fig. 530. Third Baker Operation—Putting on New Tire 
and Lowering Wheel 


until the wedges swing out and down, as shown in Fig. 528. As 
mentioned previously, this means quite a little loosening, for the 
wedges have a long lip 
which projects under the 
tire-carrying rim. When 
this has been done, and 
as each one swings down 
out of the way, it is 
tightened just enough to 
prevent the wedges from 
swinging back. 

This done, the wheel 
is jacked up off the 
ground, as shown in Fig. 

529, and the point of the 
tire tool is inserted be¬ 
tween the felloe band 
and the rim carrying the 
tire at the point opposite the valve, where, it will be remembered, the 
wedges were loosened, and the rim will be almost free. By prying 
the tire-carrying rim out¬ 
ward and working around 
it toward the valve and 
back again, it will finally 
be loosened to a point 
where, with the valve at 
the bottom, the rim and 
tire can be slipped off 
without lifting it. The 
extra tire and rim are 
now put in place. 

This is shown in Fig. 

530, where the reverse of 
the operations shown in 
Fig. 529 and just de¬ 
scribed is followed, that 
is, the valve stem hole is revolved to the top, the valve stem inserted, 


Fig. 531. Fourth Operation—Tightening Bolts on 
^ the New Tire and Rim 


the rim pressed into place all around, then the wheel is revolved until 








664 


GASOLINE AUTOMOBILES 




Fig. 532 Fifth Operation—Starting to Take 
the Rim out of the Tire—Beginning 
to Pry Short End 


Fig. 533. Sixth Operation—Forcing Down the 
Short End of Rim 

( 




Fig. 534. Seventh Operation—Prying under 
the Loose End of Rim 


Fig. 535. Eighth Operation—Raising the Free 
End of Rim, Using Both Hands 



Fig. 536. Ninth Operation—Inserting 
Valve Stem and Beads in 
End of Rim 


Fig. 537. Tenth Operation—Prying Tire 
Away from Rim to Let Latter 
Slip into Place 









GASOLINE AUTOMOBILES 


665 


the valve stem comes to the bottom, so that the two wedges 
which have not been loosened are nearest the ground. Then the jack 
is let down and removed, the whole weight of the wheel coming on 
the bottom point where the wedges are already tight, never having 
been loosened. 

This action is necessary as, with the weight on the other points 
where wedges are still loose, it would be necessary to work against 
the car weight. At this point, as Fig. 531 shows, the nuts are loosened, 
using the special brace until the wedges can be inserted under the 
rim. This done, the nuts are tightened to hold them there. This 
tightenipg is continued until the little studs, or lips, in the rim rest 
on top of the outside edge of the felloe band, using the tire tool to 
force them in, if necessary. The new tire carried is supposed to be 
ready for use, that is, inflated to the proper pressure, so that these 
four actions complete the work of making a roadside change. 

When it is desired to repair the tire which has been removed, 
it is carried home on its rim just as taken off the car wheel, and the 
rim is removed from the casing as follows: Rim and tire are laid 
flat on the garage floor, as shown in Fig. 532, so that the outer end 
of the diagonal cut in the inside of the rim which is farthest from the 
valve stem is uppermost. An inside plate will be found on the rim 
which covers the two rivet heads on either side of the cut, with a 
central hole for the valve stem. This plate is called the anchor plate 
and must be removed. To do this, begin at the short end of the rim, 
which does not have the valve stem—as, in this position, it will be 
held in the long end—and insert the sharp end of the tire tool or a 
screwdriver under the bead or between the bead and the rim. 

These two actions, as shown in Fig. 533, bring the two short 
sides of the rim closer together and thus reduce the diameter. When 
the extreme end has been freed in this way, the operation is repeated 
some 5 or 6 inches farther around, that is, that much farther away 
from the slit. This done, a considerable portion of one end will be 
free. Then turn the rim and tire over so that this free part comes at 
the top instead of at the bottom and, standing on the part which is 
still tight, insert the tool between the rim and the entire tire. 

This frees the entire end, but, to make sure, the tool must be 
moved a little farther along so as to free more of it. When enough has 
been freed to allow grasping it with both hands, as shown in Fig. 535, 


666 


GASOLINE AUTOMOBILES 


the tool is dispensed with and, taking a firm grip on the rim, at the 
same time standing on the tire at the point where tire and rim still 
contact, pull upward strongly. When followed all the way around 
this pulls the rim entirely out of the tire. 

Having the casing and tube free, they may now be inspected and 
repaired. When this is done, or if it is not done, and a new tire or tube 
or both are used, the worker is ready now to replace the rim. This is 
practically the reverse of the method just followed out. As shown in 
Fig. 536, the rim is laid on the floor; then the end which has the valve- 
stem hole drilled in it is raised, and the valve stem inserted. Next 
the beads are pulled into the rim, it being necessary to press them 
together somewhat tightly in order to do this, but, with a little prac¬ 
tice, it soon becomes an easy matter. All this is done with the other 
part of the rim underneath the tire. 

The inserted end of the rim is followed around with the thin 
end of the tire tool, as shown in Fig. 537, the position of the tire 

above the rim allowing the work¬ 
man to stand on it and thus use 
his weight to press the two sides 
of the tire together and, at the 
same time, to force them into the 
rim. This operation is followed 
right around the inside circum¬ 
ference of the tire, the free, or 
short, end of the rim being the 
last part to enter. On account of 
the shape of the joint or cut in it, this should slip readily into its 
proper place, but if it does not, the thin end of the tool can be used to 
pry it into place, or a hammer can be used on the longer side to 
drive it in. 

The rim being fitted snugly into place all around, the anchor 
plate is inserted, Fig. 538, to prevent the short end slipping out again, 
and the tire is ready for inflation. If it is to be carried as a spare 
tire, the dust cap should be screwed into place over the valve stem, 
so as to preserve the threads which might be damaged in handling. 

Rim with Straight Split. This covers the action of practically all 
the demountables in which the transversely split rim is used, necessi¬ 
tating the removal of the rim and tire from the wheel before the 



Fig. 538. Eleventh Operation—Inserting 
Anchor Plate 



GASOLINE AUTOMOBILES 


667 





Fig. 539. One-Piece Rim, Showing Right-Angled 
Split and Locking Device 


tire can he taken off the rim. However, not all rims are split on a 
diagonal as is this one, and Fig. 539 is presented to show this single 
feature on another rim, which otherwise is somewhat similar. Here 
the rim is split at right 

angles, having a plain thin 
rectangular plate A attached 
to the free end, or that which 
is removed first, while the 
other end has a swinging flat 
tapered plate with a cam¬ 
shaped /end B, the action of 
which is to expand the rim 
to its fullest diameter and 
lock it there. In the top 
figure, it is locked—that is, 
the rim is expanded as it 

Would be when in use and just Courtesy °f Standard Welding Company, Cleveland, Ohio 

after it had been removed for 
replacement. When the rim 
is to be removed from the 
tire, the latch B is swung out 
of the way, as shown in the 
lower figure, when the catch 

C which holds the two ends 

\ 

together can be opened by 
lifting the tire with this 
portion at the bottom and 
then dropping it a couple of 
times. This done—usually 
this action will be accom¬ 
panied by the free end spring 
inside the fixed end—con¬ 
tinuation of the removal is an 
easy matter. The rim shown 
is the Stanweld No. 20. 

Comparison of Continuous Holding Ring Type ivitli Local Wedge 
Type. To return to demountable-detachable rims, these may and do 
include a number of those quick-detachable forms previously shown 


Fig. 540. Sections through Two Popular Forms 
of Demountable-Detachable Rims 





























































668 


GASOLINE AUTOMOBILES 


and described. In Fig. 540, a pair of typical forms is shown, that at 
1 being fitted for a clincher tire, while that at 2 is for a straight side. 
Looking at the detachable part of the rim, 1 will be recognized as 
that previously shown at 3, Fig. 521, where it was described as a 
universal rim, the inversion of the two rings converting it from a 
clincher to a straight side, or vice versa. Similarly, 2 will be recog¬ 
nized as the form of detachable shown at 3 in Fig. 524. 

Here, however, both are fitted to be used as demountables, 
this being accomplished by the formation on the under side of the 
band of a pair of wedge-shaped projections. The felloe band is so 
made and applied that it forms one surface to contact with one of 
these wedges, while the other is formed variously. At I, a separate 
ring is used with the flat outside clips to hold this against both 

felloe band and rim, while at 
2 the wedges or clips have 
an extension which presses 
against the outer wedge on 
the rim. This latter distinc¬ 
tion divides these two into 
the two classes mentioned 
previously — one into the 
continuous holding ring class, 
the other into the local 
wedge type. 

These forms are shown 
to illustrate this point and 
also because, despite this 
difference, they have practically similar felloe bands. This felloe 
band—that is, of the form shown in 2 —has been recommended as a 
standard for all demountable-detachable rims. Another and different 
example of the clamping-ring demountable-detachable type is shown 
in Fig. 541, this being the Firestone rim. Here, it will be noted, is 
the felloe band just mentioned, while the detachable-rim portion is 
that previously shown at 1 in Fig. 523 as having the Z-shaped locking 
ring and being adapted to clincher tires only. The rim band is 
made with the two wedge-shaped projections on its underside. 

Perlman Rim Patents. Late in the summer of 1915, considerable 
consternation was caused among tire and rim manufacturers when 



Fig. 541. Section of Tire and Rim of Firestone 
Demountable Tire 





























GASOLINE AUTOMOBILES 660 

* 

it became known that the Perlman rim patent had been adjudged 
basic by the courts, and that, on the strength of this decision, an 
injunction had been issued against the Standard Welding Company, 
of Cleveland, Ohio, some few of whose rims have been previously 
described. Perlman’s original patent was applied for on June 29, 
1906, and, in addition to this record, the fact was established that 
the owner had a Welch car which had traveled over 150,000 miles 
and on which were a set of the original rims. The case dragged 
through the courts and was discontinued some seven or eight years 
ago. Perlman persisted, however, although he had to revise and 
alter his application many times; the basic patents were finally 
allowed, and issued to him in February, 1913. This means, of course, 
that the patent will not expire until 
the year 1930. 

Perlman’s locking elements and 
the principle involved are shown in 
Fig. 542, which is a section through 
the rim and felloe. In Perlman’s suit, 
it was claimed that the wedge end of 
the bolt which was covered in his 
patent, included all wedge-operating 
rims, whether actuated from the 
center, as in Fig. 542, or from the side. 

This contention was supported by the 
court, and negotiations are now in process between Perlman and many 
manufacturers of the so-called local wedge type of rim. As this would 
appear to cover all the rims shown and described in Figs. 525 to 541, 
inclusive, the influence of this decision upon the industry can be 
imagined. Moreover, the length of time which this basic patent has 
to run precludes the possibility of delaying action by prolongation 
of suits, as has been done in similar cases. A notable example of 
this is the case of the Selden automobile patents, which were fought 
on one ground or another over a long period of years. 

Standard Sizes of Tires and Rims. As might have been noted 
in going over the above discussion of tires, plain rims, detachable 
rims, and, finally, demountable rims, all these different constructions 
require widely differing wheel sizes. It has been proposed to stand¬ 
ardize wheels, that is, the outside diameter of the felloe and with 



Fig. 542. Section of Perlman Rim, 
Showing Locking Device 





















670 


GASOLINE AUTOMOBILES 


it the thickness of felloe bands as well as their shapes or contours, 
one for each tire cross-section. The proposed reduction of tire sizes 
to nine standards is as follows: 30- by 3-inch, 30- by 3|-inch, 32- by 
3§-inch, 32- by 4-inch, 34- by 4§-inch, 36- by 4|-inch, 38- by 5|-inch 
and probably 36- by 5-inch, supplying these sizes and these only to 
manufacturers of cars; additional oversizes are allowed for car users, 
one for each size above, that is, 31- by 3§-inch for 30- by 3-inch, 31- 


Tire Seal Line 



F Sections4-" 



felloes for *3, *30 felloes for Felloes for Felloes for felloes for 

fill One Piece Kelsey Rims Firestone Rims Slanweld Stonweld 

Split Rims *40Rims *60Rims 

Tire 5eal Line 



G Sections Si "p6 " 

Fig. 543. Typical Felloe, Band, and Rim Sections for Popular Demountable Rims 

by 4-inch for 30- by 3|-inch, 33- by 4-inch for 32- by 3§-inch, 33- by 
4J-inch for 32- by 4-inch, 35- by 4J-inch for 34- by 4-inch, 35- by 5- 
inch for 34- by 4|-inch, 37- by 5-inch for 36- by 4J-inch, 39- by 6-inch 
for 38- by 5|-inch and probably 37- by 5|-inch for the 36- by 5-inch. 
Rim standardization will follow the adoption of these sizes. In this 
event, the standardization of demountable rims will come in time. 

At the present, there is a wide range of difference, as will be 
noted in the drawing, Fig. 543, which shows felloes for the most 






































































































































GASOLINE AUTOMOBILES 


671 


widely used demountable rims, depicting the band and rim in each 
case. The drawing should be read crosswise, each horizontal line 


showing the differences to be 
found in the makes mentioned in 
that particular tire cross-section 
size. Thus, the D sections show 
the differences for 3§-inch tires, 
E those for 4-inch tires, F those 
for 4J- and 5-inch tires, and G 
those for/ 5J- and 6-inch tires, 
rims for which are not produced 
by all makers. 

Other Removable Forms. 
Outside of the regular range of 
wood wheels and the standard 
tires for them, any different wheel 
calls for a different treatment. 
As has already been mentioned 
under the subject of Wire Wheels, 
few of these have anything but a 
solid one-piece clincher rim; first, 
because the wheel itself is remov¬ 
able, thus making it as easy to 
change wheels as to change rims 
in the ordinary case; and second, 
to save weight and complication. 

Demountable for Wire W heels. 
However, demountable forms 
have been produced for wire 
wheels, one being shown in Figs. 
544 and 545. This is the G-R-C 
double Q.D. rim as the makers 
prefer to call it, in action a de¬ 
mountable-detachable form, the 
clincher rim being of the straight 
split type, in fact, a Stanweld 
No. 20. This is made with a 
double wedging surface on the 



Fig. 544. Operating Device on the Ashley- 
Moyer Double Q.D. Rim for Wire Wheels 






























































672 


GASOLINE AUTOMOBILES 



outside and a single one on the inside. The latter contacts with 
another on the false rim to which the wire spokes are attached, as does 
also the inner wedging surface on the outer wedge. The outer wedg¬ 
ing surface is made so as to come just above a fairly deep slot in the 
false rim. In this is placed a ring with a double wedge-shaped upper 
edge and a square lower edge. This ring is split at one point and 
locked in the highest position at the point diametrically opposite. 

At the split point, a pair of bent-arm levers, Fig. 544, are 
connected to the two ends. Attached to a middle point of each of 

these is one end of an inverted U- 
shaped member, the center and 
upper part of which form a bear¬ 
ing for a locking stud, which is 
attached to one end of the ring. 
Above this is placed a nut. As 
will be noted, this forms a toggle 
motion, the action of which is 
to expand the whole ring when 
the nut is screwed down and to 
contract it when the nut is 
screwed up. 

This is the precise action 
used, the single ring forming the 
whole locking means, and being 
actuated by the toggle mech¬ 
anism through the medium of 
screwing the nut up or down. 
While at its best on wire wheels because of its simplicity, this rim 
is, of course, applicable to wood wheels. At present, its makers 
are specializing on the wire-wheel forms. 

Parker Rim-Locking Device. Another rim-locking device which 
does not come under any of the standard divisions, being devised 
for use on the Parker hydraulic wheel, previously shown in Fig. 
502, is the Parker modification of the former Healy rim. As shown 
in Fig. 546, which shows the end of a steel spoke in section, this is 
made with a cup at the upper and inner end, while at the outer is 
a loose clip, through which passes a bolt with a head on the outside. 
Tightening the bolt by means of the external head draws the clip 


Fig. 546. Construction of Parker Hydraulic 
Steel Wheel Spokes, and Operation of 
Locking Device for Rims 





GASOLINE AUTOMOBILES 


673 


up the incline at the bottom of the cup, against the wedge on the 
underside of the rim, the amount of pressure exerted depending 
solely upon that applied to the bolt head. As the two wedge shapes 
oppose each other, this holds the rim as firmly as is possible. It 
will be noted that this construction does away altogether with the 
use of felloe bands or false rims used on other forms of rims or wheels, 
thus saving much weight. Moreover, a great part of the weight 
is saved at the outside, where the flywheel effect of rapid rotation 
is thus lessened. Moreover, the absence of additional metal here 
would give the tire more chance to radiate its heat, and thus would 

preserve it better. This construction, considering its many advan- 

/ 

tages, should have a wide use. 

Similarly, with all demountable rims, the tendency is toward 
wider use, with which comes lower cost, as well as a better under¬ 
standing of their use, abuse, attachment, and detachment. With 
the standardization of tires to a few standard sizes, say 9 instead 
of 54, it will be only a few years before all kinds of rims, including 
demountables, will be standardized, at which time the latter will 
come into universal use. 

TIRE CONSTRUCTION 

Composition and Manufacture. Tires consist of two parts, the 
tube and the shoe, or casing. The former is a plain ring of circular 
cross-section, made of pure rubber, containing an air valve, and is 
intended only to hold the air. The shoe, or casing, on the other 
hand, provides the wearing surface, protects the air container within 
from all road and other injuries, and constitutes or incorporates the 
method of fastening itself to the wheel. In its construction are 
included fabric—preferably cotton—some pure rubber, and much 
rubber composition, the whole being baked into a complete unit by heat 
in the presence of sulphur, which acts somewhat as a flux for rubber. 

Considering a typical tire, there enters into its make-up, starting 
from the inside, six or seven strips of frictional fabric, that is, thin 
sheets of pure gum rubber rolled into intimate contact with each 
side of the cotton, making it really a rubber-coated material. Next, 
there is the so-called padding, which is more or less pure rubber, has 
a maximum thickness at the center of the tread, and tapers off to 
nothing at the sides, but usually carrying down to the beading. 


674 


GASOLINE AUTOMOBILES 


Above this tnere is placed a breaker strip, consisting of two or three 
layers of frictioned fabric impregnated in a rubber composition. 
This, too, is thickest at the center and tapers off to the sides, but 
ends at the edge of the tread. Finally, there is the surface covering, 
called by rubber men the tread; this contains very little pure rubber, 
being thickest at the center and extending with gradually decreased 

thickness almost down to the 

* 

bead. 

The last two of this series of 
layers constitute the real wearing 
surface of the tire, and when the 
surface is so worn that the breaker 
strip may be seen, it is time to 
have the tire retreaded. When 
the wear has gone through this, 
if the padding be fairly complete, 
retreading will still save the tire, 
but if wear has gone clear down 
through that so as to expose the 
fabric, the show must be run to a 
finish and then discarded. 

All this construction can be 
noted in Fig. 547, which shows a 
section through a tire, with the 
inner tube in place, the section 
being taken so as to pass through 
the center of the tire valve. This 
should be borne in mind when 
examining this figure, for the 
location of the inner tube inside 
the tire, as previously described, 
is likely to be misleading. 

Bead. In the reference to 
tire construction, no mention has been made of the bead. This is a 
highly important part of the tire, for it is the part which holds 
it in place on the wheel. It is made of a fairly hard rubber 
composition, the fabric being carried down on the sides so as to cover 
it. In a cross-section, it has a shape very close to an equilateral 



Bead 
Filler 


Valve Inside 


XJ> 


Fig. 547. Section through Assembled Tire and 
Tube, Showing Construction and Parts 
of the Tire and Tire Valve 































GASOLINE AUTOMOBILES 


675 


Threads for Cap 


■Robber Packing 


Valve Seat 


Rir Vent 


triangle resting on its base; around the wheel it is curved to fit the rim. 
The method of attaching the tire has a considerable influence on bead 
construction, since, in the clincher type of tire, in which the shoe must 
be stretched on over the rim, the bead must be extensible in order to 
insure easy mounting. In the quick-detachable and straight-side 
forms of tire there is no need for this stretching, so the bead can be 
made of stiff and rigid material as well as cut down somewhat in size. 

The straight-side or Dunlop type of tire is seldom made with 
much of any bead, the layers of fabric being carried straight down. 
A more modern form of tire has a 
pair of w6ven-wire cables incor¬ 
porated in the bead to make it 
stiffer and stronger, and this is 
said to have been very successful. 

As has been pointed out pre¬ 
viously, this could be done only 
with the quick-detachable form, 
not with the clincher type. 

In both the clincher and the 
quick-detachable forms, the bead 
holds the tire to the wheel by 
means of parts of the rim, which 
bear on it from above, as well as 
sidewise, the internal pressure 
when the tire is inflated pressing 
it against these parts very firmly. 

In both the clincher and the quick-detachable forms, the bead 
holds the tire to the wheel by means of parts of the rim, which bear 
on it from above, as well as sidewise, the internal pressure when 
the tire is inflated pressing it against these parts very firmly. 

Tire Valves. In Fig. 547 there is shown a section through the 
tire valve but on a small scale. As this is a very important part 
and little understood, a larger view is shown in Fig. 548. This is in 



Spring 
Valve Stem 


Valve Stem Guidt 


Tire Valve Stem 



Valve Closed 


Valve Open 


Fig. 548. Views of Tire Valve, Showing 
Closed and Open Positions 


two parts, A at the left showing the valve closed, and B at the right 
indicating the position of the various parts when the valve is open. 
Note that the lower part of the valve is hollow, so that air inside of 
the tire has access to the valve seat. Note that the valve is held 
down on this by the threaded portion above it. This valve seat 
















































676 


GASOLINE AUTOMOBILES 


forms a slight taper which rests against an equally slight taper 
inside of the valve stem. 

One condition of the tire valve holding air pressure is that the 
two valve seats be clean and smooth and free from scratches or cuts 
and foreign matter. Now it will be observed that the valve-seat 
portion of the valve has a hole through the center, in which the 
stem is a loose fit. This large hole passes all the way up through the 
threaded portion. The stem has a projection below the valve seat, 
which* normally is held up against the bottom of the seat by the 
spring, this being strong enough to hold it up so tightly that no air 
can pass between the two. There are other conditions for valve 
tightness. The spring must be strong enough to hold these parts 
together; and the. surf aces must be clean and true so that when 
held together, no air can get through. 

Action of Valve. The action of the valve is this: When air 
is pumped in, it passes down around the central stem until it 
meets the projection, which it forces down against the pressure of 
the spring and, when there is air inside, against the pressure of the 
internal air. As soon as this is pressed down, the air passes in, and 
if the external pressure is stopped, as at the end of a stroke of the 
pump, the spring and the internal pressure push the projection 
back into place, and no air can escape. On the next pressure stroke 
of the pump, this is repeated, the whole process continuing until the 
tire is filled. 

Leaky Valves. It will be noted that with a good clean spring, 
projection, and valve seat, the pressure of the air itself holds the 
valve tight. Thus, when a valve leaks, it is a sure sign that some 
part or parts of it are not in good condition. If the valve is not 
screwed down far enough, air can leak out around the valve seat, 
so that leakage may be remedied by screwing the whole valve farther 
down into the stem. If the valve stem is too tight a fit in the central 
hole, it may stick in a position which allows air to pass. This can 
be remedied by a drop of oil placed on the stem and allowed to 
run down it. But not more than one drop should be used as oil is 
the greatest enemy of rubber, and the tube with which the valve 
communicates is nearly pure rubber. 

If the spring is too weak to hold the projection against the 
bottom of the valve seat, the valve will leak. This can be remedied 



GASOLINE AUTOMOBILES 


G7? 


by taking out and cleaning the spring, also stretching it as much as 
possible. In general, however, the best plan of action with a 
troublesome tire valve is to screw it out and put in a new one. These 
can be bought for fifty cents a dozen, and every motorist should 
carry a dozen in a, sealed envelope, also a combination valve tool. 
When trouble arises with the valve, or a tire leaks down flat with 
no apparent cause, screw out the valve with the tool, screw 
in a new one, make sure it is down tight, and pump up again. The 
few cents it will cost to throw away a valve, even if it should hap¬ 
pen to be good, will be more then compensated for by the time 
saved. Another point is that the whole valve assembly is so very 
small that it is difficult to handle. 

Washing tires often is a good practice, since water does them no 

harm, while all road and car oils and greases will be cleaned off, 

• 

nearly all of these being injurious. Frequent washing will also serve 
to call the attention of the owner to minor defects while they are still 
small enough to be easily repaired, and thus they are prevented from 
spreading. When not in use, tires should be wrapped, so as to be 
covered from the light, and put away in a dry room in which the 
temperature is fairly constant the year round. They will not stand 
much sunlight, nor many changes in temperature. Cold hardens 
the tires and causes the rubber to crack. Heat has a somewhat 
similar effect and also draws out its life and spring. 

In general, of all things to be cared for and repaired promptly, 
no one thing is of more importance than the tires. If this rule is 
kept in mind, better satisfaction in the use of the car will result. 
So, too, with other repair work; if tools and appliances are made 
available and repairs made as soon as needed, the car will be better 
understood and give more satisfaction than if the opposite course 
be pursued. A few months of use of a car will do more to emphasize 
this than any amount of talk. Keep your car in good condition 
and you will reap the benefits of the little work you do upon it. 

TIRE REPAIRS 
Repair Equipment 

Vulcanization of Tires for Repair Man. In practically all of the 
following material the point of view is that of the professional repair 
man, or of the garage man about to take up tire repairs, as dis- 


678 


GASOLINE AUTOMOBILES 


tinguished from that of the average owner or amateur repairer. The 
lesser tire injuries and their repairs are handled from an amateur 
standpoint in another part of this work. 

Vulcanization, to the unitiated, sounds very mysterious, but 
it really is nothing more or less than cooking, or curing, raw gum 



Fig. 549. Small Vulcanizing Outfit for Single Casing of Six Inner Tubes 
Courtesy of C. A. Shaler Company , Waupun, Wisconsin 

rubber. In the processes of manufacture a tire is cooked, or cured, 
all the component parts supposedly being united into one complete 
whole. A tire is repaired preferably with raw gum or fabric prepared 
with raw gum, and, in order to unite this to the tire, vulcanization 
or curing is necessary. The curing, in addition to uniting the parts 


























GASOLINE AUTOMOBILES 


679 


properly, gives the proper strength, or wear-resisting qualities, which 
raw rubber lacks. 

Types of Vulcanizing Outfits. Shaler Vulcanizer. This curing, 
or cooking, is clone by the application of heat, in a variety of ways. 
Generally, very small individual vulcanizers have a gasoline or 
alcohol cavity, holding just enough of the liquid so that when lighted 
and burned the correct temperature will be reached and held for the 
correct length of time. The larger units are operated by steam or 
electricity; the latter is preferred for its convenience, but the former is 
used by the majority of repair men. The source of heat is immaterial 
so long as the correct temperature is reached and maintained for 
the right lengh of time. Too hot a vulcanizer will burn the rubber, 
while too low a temperature will not give a complete cure. 

For the average small repair man, the outfit shown in Fig. 549 
will do very nicely, at least to start with. This will handle a single 
casing or six tubes, or in a press of work, both simultaneously. This 
outfit is operated by gasoline, contained in the tank shown above 
at the right, but the same outfit can be had with pipe arrangements 
for connecting to a steam main, or for electric heating. In the case 
of either gasoline or steam, there is an automatic temperature con¬ 
trolling device which is a feature of the Shaler apparatus. As shown, 
casings are repaired by what is known as the “wrapped tread method”, 
the repair being heated from both inside and outside at once, the 
outside being wrapped. Tubes are handled on the flat plate, shown 
in the middle of the framework, the size of which is 4J by 30 inches, 
this being sufficient, so the makers say, to handle six tubes at once. 

Haywood Vulcanizer. For larger work, a machine something 
like the Haywood Master, shown in Fig. 550, is excellent. This is 
a self-contained unit, carrying its own gasoline tank, steam generator, 
and other parts. It handles four casings at once, while the tube 
plate G, 5 by 18 inches, is large enough for from three to four tubes, 
according to the allowance per tube made in the Shaler outfit. The 
separate vulcanizers are not designed for the same part of a casing, 
a side wall and bead vulcanizer being shown at D, a sectional vul¬ 
canizer for large sizes at E, a sectional vulcanizer for small and 
medium sizes at F, and a side wall and bead vulcanizer for both 
clincher and straight-side tires at H. The gasoline tank is marked 
C y with vertical pipe in which is the gasoline cut-off valve K. This 



G80 GASOLINE AUTOMOBILES 

leads down to the gasoline burner M, where the gasoline in burning 
vaporizes the water into steam. The water gage L, which indicates 
the amount of water available, is placed on the side of the steam 
generator A. Above this steam generator is the steam dome at /i, 


Fig. 550. Master Vulcanizer with Self-Contained Steam Generator 
Courtesy of Haywood Tire and Equipment Company, Indianapolis, Indiana 

from which the steam pipes lead to the various molds. The returns, 
or rather drips, will be noted, also the steam gage (not marked) and 
the cut-off valve in the supply pipe to the sectional molds. In addi¬ 
tion to the molds shown and a full supply of parts and tools, sec¬ 
tional vulcanizers for 2J- and 3-inch tires, relining mold for 2J-, 3-, 















GASOLINE AUTOMOBILES 


681 


and 3 2 -inch tires, and relining mold for 4-, 4J-, 5-. and 5J-inch casings 
come with the device. 

This outfit with the extra molds, described but not shown, gives 
a very complete equipment for the small shop doing average 



Fig. 551. Battery of Vulcanizing Mold for Various Sizes of Tires 


repairing. In fact, when a shop outgrows this type of equipment, 
it must specialize in tire work and purchase special equipment. 

Separate Casing Molds for Patch Work. In the way of sepa¬ 
rate molds for casings, an excellent example of the localized heat 
type is shown in Fig. 551. By this is meant the form designed to 
vulcanize a small short section of a tire. The illustration shows 
five sections capable of handling, respectively, 2J-, to 3-inch (motor¬ 
cycle), 2|- to 3-inch (small car), 3^- to 4-inch, to 5-inch, and 5J- to 
6-inch tires, thus covering the entire range. These molds have a 
special arrangement in that the heating portion is divided into three 
sections, into each of which steam can be admitted separately. This 
allows the use of one, two, or all the sections, according to the nature 
of the repair. 

In Fig. 552 is shown how it is 
possible, with this apparatus, to vul- ^ x 
canize the tread portion only by ^ 
admitting steam solely to the larger 
bottom steam chamber around the 
tread, similarly, with the right-hand 
bead or side wall or the left-hand bead 
or side wall. When a complete sec¬ 
tion is to be vulcanized, all sections 
are opened. The importance of this 
will be realized in a simple consideration of the fact that the tire itself 
has already been vulcanized and further heat is not only not good for 
it, but is distinctly bad, as it deteriorates the rubber. Where the heat 



Fig. 552. Section of Vulcanizer, 
Showing Steam Cavities 























G82 


GASOLINE AUTOMOBILES 


is needed, however, is not the raw rubber which has just been added at 
the repair point, this being practically useless until it has been cured. 

Vulcanizing Kettles. Horizontal Type. When it comes to 
vulcanizing an entire tire, as, for instance, when a new tread has been 

put on, or other very large repair, 
what is known in the trade as 
a “kettle” is needed. This is 
simply a heavy steel tank, large 
enough to take one or more entire 
tires, steam being admitted to its 
interior to vulcanize them. The 
kettle shown in Fig. 553 has a 
capacity of two casings 36 inches 
in diameter or smaller. It is of 
the type in which no bolts or nuts 
are used for fastening the cover, 
this being held fast by the pro¬ 
jecting lugs which lock under 
other projections on the top of 
the kettle when the cover is 
turned. A special rubber pack¬ 
ing ring also is used, Fig. 554, 
effectually sealing the kettle 
against steam leakage. This kettle resembles a doughnut in shape, 
the tires lying within the circular cavity. 



Large Vertical Type. When the work goes beyond the capacity 
of size and type of tank or kettle shown in Fig. 553, which will handle 



Fig. 553. Vulcanizing Kettle, Horizontal 
Type 



































GASOLINE AUTOMOBILES 


683 


two casings at a time, and at least two, perhaps four, kettles full 
an hour, that is, from 40 to 75 casings a day, it becomes necessary 
to use a larger type of kettle, made in vertical types only. These 
consist simply of large round steel shells with hinged heads, into 





Fig. 555. Shaler Electrically Heated Inside Casing Form 


which the tires can be rolled and piled, after which steam is admitted to 
the whole interior. They vary in size from 36 inches inside diameter 
by 24 inches in length to 48 inches diameter by 40 inches in length. 

Inside Casing Forms. Another 
requisite of the tire specialist is an 
inside casing form, such as is shown 
in Fig. 555, or something similar. 

Many tire repairs are inside work, 
and even on those which are 
external, it is important to have an 
inside form against which the tire 
can be pressed and firmly held while 
vulcanizing. This particular form 
is heated by electricity, the wires 
being shown at the left; it is 14 
inches long and has an external 
shape to fit the inside of all casings. 

Side=Wall Vulcanizer. A shop doing a great deal of work can 
use to good advantage the side-wall vulcanizer shown in Fig. 556. 



Fig. 556. Side-Wall Vulcanizer 






























G84 GASOLINE AUTOMOBILES 


It has a single central member through which the steam passes, and 
also has bolted-on side plates, the insides of which are formed to suit 
either clincher or straight-side tires; In the figure, the side plates are 
not both in place, one being shown on the work table below. The 
brace shown is used to remove the clamping nuts quickly and easily. 
This form is very useful on all side-wall or bead operations. It applies 
greater pressure along these parts of the tire than an air bag; it exactly 


Fig. 557. Retreading Vulcanizer with Tire in Position 
Courtesy of Haywood Tire and Equipment Company, Indianapolis, Indiana 

fits the tire, and the size and shape make it possible to vulcanize a 
36-inch tire in four settings. 

Retreading Vulcanizers. Retreading vulcanizers differ from 
the sectional molds of Figs. 549, 550, and 551 in that the heat is 
applied at one particular point or, rather, strip along the middle of 
the top surface of the casing and extending down only as far as 
the side walls. Such a device, shown in elevation in Fig. 557, and 
in enlarged sectional detail in Fig. 558, is used solely for retreading 
or vulcanizing a new tread strip around the tire. The complete 
unit extends around about one-third of the whole tire surface so that 


GASOLINE AUTOMOBILES 


685 



when putting on a complete new tread the mold must be used three 
times. The section, big. 558, is numbered as follows: casing, 2; 
inner mold, 1; new tread to be vulcanized, 3; vulcanizer proper, 4; 
clamp, o; and steam space within which the heating is done, 6. 

Layouts of Equipment. There are two ways of installing an 
outfit somewhat like that just described, namely, by the non-return 
system and by the gravity- 
return system. 

Non-Return Layout. A 
typical installation according 
to the non-return system is 
shown in Fig. 559. A steam 
trap must be placed in the 
system to remove the water 
and discharge it either into 
the sewer or into a tank so 
that it can be used again. 

In the figure there is shown a 
tube plate, a three-cavity 
sectional vulcanizer, two in¬ 
side molds, and a medium 
size kettle of the vertical type 
placed in order from right 
to left. A pressure-reducing 
valve is shown which permits 
the use of a higher pressure 
in the boiler, thus maintain¬ 
ing an even steady pressure 
on the vulcanizers regardless 
of fluctuations at the boiler. 

Gravity-Return Layout. When the coil steam-generator or flash 
type of boiler is used, the gravity-return system is utilized, this being 
a method of piping bv means of which the condensed steam is returned 
to the coil heater to be used over again. This makes it necessary to 
set the apparatus so that the water of condensation will run back to 
the coil heater, which means that the pieces must be in a series, each 
successive one being set a little lower down to the boiler. Figs. 
560 and 561 show a side view and plan view, respectively, of a small 


Fig. 558. Section of Retarding Vulcanizer 

Courtesy of Haywood Tire and Equipment 
Company, Indianapolis, Indiana 













GASOLINE AUTOMOBILES 



Fig. 559. Diagrammatic Layout for Non-Return Vulcanizing Plant 









































































































































































































GASOLINE AUTOMOBILES 


687 


plant arranged on this plan. The outfit consists of the coil heater, 
which may be fitted to burn gas or gasoline, two inside molds, a large 
tube plate, and a three-cavity sectional vulcanizer. The outfit 



Fig. 569. Elevation of Gravity-Return Vulcanizing Plant 


differs from Fig. 559 only in the absence of the kettle; on the other 
hand, the tube plate in Fig. 560 is larger. 

Small Tool Equipment. In addition to these larger units, the 
well equipped tire repair shop should have a considerable quantity 
of small tools, among the necessities being those shown in Fig. 562. 
At A is shown a flat hand roller and at B a concave roller. C shows 
an awl, or probe, which is used for opening air bubbles and sand blis¬ 
ters, D is a smooth stitcher; F a rubber knife, of which two sizes are 
advisable, a large and a small; and G a 10-inch pair of shears for 



trimming inner tube holes, cutting sheet rubber, etc. H is a steel 
wire brush for roughing casings by hand; a preferable form is a 
rotary steel wire type driven by power at high speed. I is a similar 















































































































Fig. 562. Collection of Tools Necessary for Vulcanizing Work 

I 

scraper and P a tread chisel; Q performs a somewhat similar function, 
being a casing scraper for cleaning the inside of a casing preparatory 
to mending a blowout. 

In addition to the small tools shown in Fig. 562, it is necessary 
to have several tube-splicing mandrels; a large number of various 
sizes and shapes of clamps for all purposes; rules, try-squares and 
other measuring tools; tweezers for handling small patches, tools 
for recutting threads on tire valves; tire spreaders, for holding casings 


688 GASOLINE AUTOMOBILES 

wire brush for roughing tubes; and J another brush with longer 
wires, also for roughing casings; K is a tread gage for marking 
casings to be retreaded; and L a fabric knife necessary in stepping 
down plies of fabric. M is a pair of plug pliers for placing patches 
inside of small tube repairs; A is a cement brush for heavy casing 
cement, another very much smaller and lighter one—preferably of 
the camel’s hair type—being used for tube cement. 0 is a hand 


MSI 

















GASOLINE AUTOMOBILES 


689 


open when working inside; a casing mandrel or tire last of cast iron 
for holding a casing when making repairs; a tread roller for rolling 
down layers of raw stock evenly and quickly; a considerable amount 
of binding tape; thermometers; and such motor-driven brushes, 
scrapers, etc., as the quantity and quality of the work warrant. 

Materials. Each repair shop must carry such a supply of tire¬ 
repairing material as the nature and quantity of its business demands. 
Among other things may be mentioned: Tread stock, rebuilding 
fabric, single-friction fabric, cushion stock, breaker strips, single¬ 
cure tube stock, combination stock, cement, quick-cure cement, 
soapstone, valve bases, valve insides, valve caps, complete valves, 
vulcanizing acid, various tube sections, tire tape, cementless patches, 
as well as many other tire accessories to sell. Many good tire-repair 
shops find a legitimate use for special tire-repairing preparations on 
the order of Tire-Doh. 


Inner Tube Repairs 

In general, all tire repairs come under one or more of the following 
headings; puncture; blowouts; partial rim cut or rim cut all around; 
and retreading or recovering, and relining. 

Simple Patches. Under the heading of punctures are handled 
all small holes, cuts, pinched tubes, or minor injuries. Generally, 
these can be repaired by putting on a patch by means of cement, 
or with cement and acid curing. When well done, this method is 
effective. This kind of a job seldom comes to the repair man, and, 
when it does, it is principally because the owner is too lazy to do the 
work. About the only two cautions necessary are relative to clean¬ 
liness and thoroughness. The tube and patch should be thoroughly 
cleaned. Again the patch should be large, well cemented, and the 
cement allowed to dry until just sticky enough to adhere properly. 
Many a simple patch of this kind has been known to last as long as the 
balance of the tube. 

Large Patches. * Cleaning the Hole . Whenever the hole or 
cut is large, it is recommended that the repair be given more serious 
attention and vulcanized. The ragged edges of the rubber should 
be trimmed smooth with the tube shears or knife, the minimum 
amount of rubber being cut away. The hole, however, should be 
made large enough to allow the insertion of an inside patch. Then 


690 


GASOLINE AUTOMOBILES 


the tube around the hole should be cleaned thoroughly. This is best 
done with a cloth wet with gasoline, cleaning not only the outside 
but the inside around the hole and at the edges. In order to make a 
good job of this, it should be gone over several times; the larger the 
hole the more care should be used in cleaning around it. 

Preparing the Patch. Having the hole well cleaned and ready, 
these cleaned parts should be painted with two coats of vulcanizing 
cement, which is allowed to dry. This must be thoroughly, not partly, 
dry. Then the proper patch is selected, the smaller size being 
sufficient for small patches, while in the case of large repairs, the 
patch should be from J to 1 inch larger all around than the hole. 
If this is not a prepared patch, one side should be cemented just as 
the tube was previously. ' If a prepared patch is used, the semi- 
cured side should be placed in, that is, with the sticky or uncured 
side toward the tube from the inside. 

When the cement on the patch is just sticky enough, it should be 
inserted and the tube pressed down against it all around, slowly 
and carefully so as to get good adhesion. Next the cavity about 
the inside patch is filled with gum or pure rubber, preferably in sheet 
form as it comes for this purpose. This is filled in until the surface 
is flush. It is preferable to use a little vulcanizing cement to hold 
this rubber in place, particularly if a piece of sheet gum is cut to 
fill the hole. 

Vulcanizing the Patch. The repair is now about half completed 
and is next vulcanized. The length of time, if steam is used, varies 
with the amount of steam pressure; if the portable gasoline or alco¬ 
hol type of vulcanizer is applied the time varies with the temperature. 
As this time variation is so wide, it is impossible to give an invariable 
rule. Thick tubes require a little longer than thin ones, large patches 
longer than small ones, wide patches more than narrow, etc. The 
vulcanizing must be carefully and thoroughly done, and, as the 
success of the whole job depends upon this one process, the arrange¬ 
ment of the tube on the plate, of the soapsttine on the new rubber 
and on the vulcanizer to prevent adhesion, of the wood or rubber 
pad above the patch, of the clamp and its pressure, should all have 
careful attention. With 60 pounds steam pressure available, from 
10 to 12 minutes is about right, with 75 pounds from 8 to 10 minutes. 1 
In any case, the rubber should be cured just firm enough not to show 


GASOLINE AUTOMOBILES 


691 


a slight indentation from the point of a lead pencil. This is a good 
test to use at first, although after a short experience, the workman 
will be able to judge of the condition from the feeling, color, and 
general appearance of the patch. 

When the size of the plate is small, the tubes should be held up 
above it out of the v r ay, partly to allow the full use of the plate 
surface, but also to keep the tubes from being damaged. 

Inserting New Section. Preparing the Tubes. In case the 
damage to the tube is too great to permit the use of a patch, for 
instance, in case a blowout makes a w r ide hole perhaps 7 inches 
or more long, in an otherwise good tube, it is advisable to cut out 
the damaged section and insert a new section in its place. Some¬ 
times old tubes of the same size can be used for this, but, if not, 
sections can be purchased from the larger tire and rubber companies. 



Fig. 563. Sketch Showing Method of Inserting New Section in Inside Tube 


In the repair, proceed as follows: After cutting out the damaged 
section, bevel down the ends very carefully, using a mandrel to 
work on and a very sharp knife. As the appearance and, to a large 
extent, the value of the repair will depend upon these beveled ends, 
this should be done in a painstaking manner. Next select the tube 
section and cut it to size, that is, from 5 to 6 inches longer than the 
section which was cut out and which this patch is replacing. This 
allows 2\ to 3 inches for the splice at each end. Bevel the ends of 
the tube as well, and, after beveling all four ends, roughen them 
with a v T ire brush or sandpaper. 

Making the Splice. Having the tube and repair section beveled 
and buffed, the ends to be joined should be coated with one heavy 
or two light coats of acid-cure splicing cement. With the tube and 
patch properly placed on the mandrels—tube on the male and patch 
on the female—turn back the end to be repaired and the end to be 


























692 


GASOLINE AUTOMOBILES 



Stone Bruise 


Sand Blister 


Chafed Side 


Pinched Tube 


Worn Tread 


Blow-out 


applied as shown in Fig. 563. At A is shown the female mandrel 
on which is the patch B, turned back from the end of the mandrel 
about the right distance, say 3 to 3J inches. On the male mandrel C 
the tube D has been turned back about 7 to 1\ inches, then turned 
back again on itself about 3 to 3| inches. 

Just as soon as the cement has dried thoroughly on the tube, apply 

a coat of acid to the patch and 
immediately place the two 
mandrel ends together and 
snap, blow, or push the end of 
the patch over on to the end 
of the tube. This frees the 
female mandrel, which can 
be laid aside. Immediately 
wind the patched portion 
(still on the male mandrel) 
with strips of muslin or inner 
tubing. In 15 to 20 minutes 
the cement will have formed 
a permanent union, the wrap¬ 
pings can be removed, and 
the tube withdrawn through 
the slot in the mandrel. 

This done successfully, 
the whole operation is re¬ 
peated for the other splice. 
If the splice does not cure 
together well, it indicates 
either that the acid supply is 
poor or else the splicing was 
not done quickly enough 
after applying the acid. 


Rim Cut 


Leaky Valve 


Fig. 564. 


Section of Tire, Showing Forms 
of Troubles 


Outer Shoe, or Casing, Repairs 

Classifying Troubles. Some of the common tire troubles— 
those of the inner-tube variety just discussed, and casing troubles 
as well—can be clearly shown by suitable illustrations. For example, 
a section through the tire showing how the troubles occur is some- 



































GASOLINE AUTOMOBILES 


G93 


times very useful, as shown in Fig. 564. Here the pinched tube 
and blowout are indicated, the results of these on the inner tube 
and also their method of repair having just been described. These 
troubles together with punctures, leaky valves, and porous rubber 
in the tubes about cover the extent of inner tube troubles. Because 
of their more complex construction, casings have more numerous 
and more varied troubles, which, consequently, are more difficult 
to repair. The more common casing troubles are blisters, blowouts, 
rim cuts, and'worn tread, the latter indicating the necessity for 
retreading. These will be described 
in order. 

Sand Blisters. The sand blister 
shown on the side of the tire, Fig. 564, 
is brought about by a small hole, such 
as an unfilled puncture hole, in com¬ 
bination with a portion of the tread 
coming loose on the casing near this 
hole. Particles of sand, road dust, 
dirt, etc., enter, or are forced into, 
this hole and move along the opening 
provided by the loose tread. Soon 
this becomes continuous and the 
amount of dirt within the break forces 
the surface rubber out in the form of a 
round knob known as a sand blister. 

This is cured by cutting open the 
blister with a sharp knife on the side 
toward the rim and picking out all 
dirt within. When the recess is 
thoroughly cleaned, the hole and the 
radial hole in the tire tread nearby 
should be filled with some form of 
self-curing rubber filler, a number of kinds of which are sold. The 
double benefit of this is to close the hole so that the trouble is not 
repeated and to keep out moisture which would ultimately loosen the 

entire tread. 

Blowouts. The blowout, which is perhaps the most important 
casing repair, may be made in two waysi the inside method, in vluch 



Fig. 565. Method of Preparing Layers 
of Fabricf or Patching Blowouts— 
Inside Method 














694 


GASOLINE AUTOMOBILES 


the whole repair is effected on the inside; the combination inside 
and outside method. 

Inside Repair Methods. Refer back to Fig. 564 for the general 
tire construction and to Fig. 565 for this particular case, the inside 
of the tire is held open by means of tire hooks and the inside fabric 
layers or plies removed for a liberal distance on each side of the 
opening. As shown in Fig. 565, a lesser amount of the second layer 
should be taken than of the first, and still less of the third and each 
subsequent one. On 3J- and 4-inch tires it is not advisable to remove 
more than two plies; on 4§-inch tires three, as shown; and on the larger 
sizes four plies. The edge of each layer of fabric should be beveled 
down thin, as well as the material directly around the blowout. 



Fig. 566. Method of Preparing Fabric for Blow-Out Patch—Inside and 

Outside Method 

Apply a coat of vulcanizing cement and when it has dried, say 
for an hour, apply another. When this has dried enough to be 
sticky or tacky, fill as much of the hole as possible with gum. When 
this is filled in level, apply the fabric patch. This is made up to 
match the fabric cutout, that is, if three layers are removed, it should 
consist of three plies stepped-up to match, and an extra last ply of 
bareback fabric unfrictioned on one side. This last layer should 
extend 3| to 4 inches beyond the ends of the patch. 

When this is properly applied and carefully smoothed down, the 
tire is placed in a sectional mold, clamped in place, perhaps wrapped 
with muslin strips to hold it tightly against the mold, and heat applied 
from the inside. This makes an excellent repair and a fairly quick 
and easy one, but it is not applicable for large blowouts; at least, it is 
not as effective as the inside and outside method. 




















GASOLINE AUTOMOBILES 


695 


Inside and Oidside Method. In the inside and outside method, 
the material is removed from the outside, stepped down, and beveled 
in the same manner as for the method just described. Fig. 566 shows 
a tire with a medium size blowout, which has been stepped down 
for a sectional repair, four plies having been removed. The rule for 
the number of plies to remove is about the same as before, except that 
in the larger sizes this should depend more on the nature of the injury. 
It should be noted, however, that in this case the plies have all been 
removed right down to and including the bead. This is done to give 
the new fabric a better hold and to make a neater job and one that 
will fit the rim better. Give the whole surface two good coats of 
vulcanizing cement, allowing it to dry thoroughly. 

Apply the same number of plies of building fabric as were 
removed, with the addition of chafing strips of light-weight fabric 
at the bead. Over this building fabric apply a thin sheet of cushion 
gum, slightly wider than the fabric breaker strip; then a thickness 
of fabric breaker strip over this; and then over this fabric another 
sheet of gum, slightly narrower than the previous sheet. All this, 
however, should be built up separately and applied as a unit and 
not one at a time, as described. These several plies should be well 
rolled together on the table. All edges should be carefully beveled off, 
especially the edges of the new gum where it meets the old, as it is 
likely to flow a little and leave a thin overlap which will soon pick 
loose. 

No fabric is removed from the inside, but the hole is cleaned, its 
edges beveled, then filled with tread gum, and the inside reinforced 
with a small patch of building fabric; over this lay two plies of 
building fabric of considerable size. Now the whole casing is placed 
in a sectional mold, a surface plate applied to the outside, and heat 
applied both inside and outside. This will heat the tire clear through 
and make a good thorough job of curing. 

Rim=Cut Repair. Partial Cut. To repair a partial rim cut, 
one or two plies of the old fabric are removed, unless it is severe, 
when three plies may be taken off. This is removed right down 
clean as explained under Blowout Repairs, and the cement and new 
materials applied in the same way, with the omission of the fabric 
breaker strip. However, care should be used to carry all building 
fabric layers not only down around the bead to the toe but up on 


696 


GASOLINE AUTOMOBILES 


the inside far enough to secure a good hold and ample reinforce¬ 
ment. If this should make the rim portion somewhat more bulky, 
remember it was a case of doing this or getting a new tire. 

Complete Rim Cut. Where the rim cutting is continuous, the 
old side-wall rubber is removed up to the edges of the tread, and 
the old chafing strips and one ply of old fabric to about an inch above 

the beads removed also. 
Cut through the side- 
wall rubber all around, 
but be very careful not to 
cut into the fabric body, 
or carcass. The whole 
of the side wall and 
chafing strips can be 
removed in one opera¬ 
tion. Apply two coats 
of cement and, after this 
is thoroughly dry, put on 
a patch consisting of one 
ply of building fabric, 

one ply of chafing strip, 

and a surface, or outside, 
ply of new tread gum. 
This is made on the table and the parts thoroughly rolled together. 
When completed, vulcanize in a sectional mold with sectional air 
bag and bead molds or endless air bag; apply to a split curing-rim 

wrap, and vulcanize in heater or kettle. The tire is repaired, but 

not vulcanized, and, with the ends of the three applied plies of mate¬ 
rial loosened to show, may be seen in Fig. 567. 

Retreading, Retreading is a job which must be done very 
carefully, not only because of the job itself, but also because this 
is probably the most expensive single job which can be done to a 
tire, and the worker should make sure before starting that the wire 
warrants this expense. It should have good side walls and bead, 
and the fabric should be solid and not broken apart. 

Reptairwg the Carcass. In the usual case, it is advisable to 
remove not only the surface rubber and fabric breaker strip, but 
also the cushion rubber beneath the breaker strip, that is,* the tire 



Fig. 567. Method of Handling Rim Cuts 






GASOLINE AUTOMOBILES 


697 


should be cleaned oft right down to the carcass, and the latter cleaned 
thoroughly. As the rubber sticks, a rotary wire brush will be found 
useful and quick. However, this should be used carefully so as not to 
gouge the carcass. After buffing, the loose particles of rubber should 
be removed with a whisk broom or dry piece of muslin. In this 
cleaning work the carcass should be kept clean and dry. Apply two 
coats of vulcanizing cement and allow both to dry; the first should be 
a light coat to soak into the surface fabric; the'second should be a 
heavy coat. 

Building Up the Tread. In building up the tread, it should 
not be made as heavy as the former tread, as the old worn and 
weakened carcass cannot carry as heavy a tread as when new. 
Furthermore, it takes longer to vulcanize a heavy tread and presents 
more opportunity for failure. In the building-up process, the pro¬ 
portioning of weights is important, and should be taken from the tab¬ 
ulation below, which represents years of experience in tire repairing: 


Size of 
Case 
(in.) 

Ply 

toward 

Fabric 

(in.) 

Second 

Ply 

(in.) 

Third 

Ply 

(in.) 

Fourth 

Ply 

(in.) 

Fifth 

Ply 

(in.) 

Last Ply 
Over All 

Complete 

Tread 

Consists 

of 

3 

2f 

3^ 




*SeeNote 

3 plies 

QA 

O 2 

2f 

3* 

41 



*See Note 

4 plies 

4 

31 

4 

4f 



*SeeNote 

4 plies 

4$ 

4 

4| 

5* 



*SeeNote 

4 plies 

5 

41 

5 

5f 

6 * 


*SeeNote 

5 plies 

5| 

4f 

5^ 

6 i 

7 

7f 

*SeeNote 

6 plies 

6 

51 

6 

6f 

71 

* 2 

81 

*SeeNote 

6 plies 


* Note—Determined by condition of case after buffing and cementing. 


Size of Case 
(in.) 

3 

.3* 

4 

41 

5 

5 * 

6 


Width of Breaker Strip 
(in.) 

1 £ 

1 8 

2 * 

2 § 

3 

3f 

4 

41 


This tread strip is built up on the table with exceeding care, 
all edges being rolled down carefully. When the strip has been 
prepared and the carcass is ready for it, one end should be centered 
on the carcass, and then the balance of the strip applied around the 
circumference, being careful to center it all around, as the workman 
in Fig. 568 is doing. After it has been applied all around, it should 



















698 


GASOLINE AUTOMOBILES 



be rolled down carefully, all air pockets opened with a sharp pointed 
awl, and the gum at the edges of the plies rolled down with the 
corrugated stitcher. When ready, vulcanize in a kettle, using an 
endless air bag with tire applied to a split curing-rim, and wrapped— 
preferably double wrapped—all around. 

Use of Reliner. Many a casing which appears good on the out¬ 
side but which really is unsafe because of fabric breaks on the inside 

can be saved, or its life temporarily prolonged, 
by the application of a reliner. By this is not 
meant the prepared canvas and fabric reliner 
which can be put in dry, but a regular built-up 
strip of building fabric, vulcanized in place so as 

to be an integral 
part of the tire. 
For ordinary 
breaks, use a 
single ply of 
building fabric 
on a casing 
which has been 
entirely cleaned 
out and which 
has had two 
coats of vulcan- 
izing cement 
thoroughly dried 
in. In the case of a bad break, use two plies 
of fabric, stepping them to fit; the under ply 
should be frictioned on two sides and coated on 
one, and the upper ply should be frictioned 
on one side only, the side toward the tube being 
bareback. Use an endless air bag for internal pressure, apply to a 
split rim, wrap, and vulcanize in a kettle from 35 to 45 minutes at 
a steam pressure of 40 pounds. 

Summary. By the application of parts of the foregoing instruc¬ 
tions and the use of much common sense, coupled with a knowledge 
of the construction, use, and abuses of tires, the repair man will be 
able to handle any form of tire repair brought to him. In starting 


F5g. 568. New method of 
Putting on New Tread 











GASOLINE AUTOMOBILES 


699 


out, perhaps he could not do a better thing than to take an old tire 
apart to see just how it is constructed. This will give a much more 
clear idea than any number of diagrams, sketches, or photographs. 

The tire repair man should remember, too, that this is no longer 
a game, but that, by means of scientific apparatus and the appli¬ 
cation of correct principles, it has been brought up to a high state 
of perfection; an expert can predict with reasonable accuracy what 
will happen in such and such a case, if this and that are not done. 
In short, the tire-repairing business within the last few years has 
been brought up to a stage where it, or any part of it, is a dependable 
operation. The tire repair man should handle all his work from 
this advanced point of view; it will pay the largest dividends in 
the long run. 

SUMMARY OF INSTRUCTIONS' 

Q. What are the units comprising the final=drive group? 

A. Universal joints; driving shaft; final gear reduction; axle- 
shaft differential; axle enclosure; torque rod, or tube, or substitute 
tor this: radius rod, or tube, or substitute for this; brakes; wheels; and 
tires. 

Q. Why are these called the final=drive group? 

A. Because they constitute the final drive of the car, beyond the * 
power-producing unit, the engine; the connecting and disconnecting 
unit, the clutch; and the speed-changing unit, the transmission. 

Q. What is the function of the universal joint? 

A. In the final-drive group, it is used to transmit power at an 
angle, as, from a horizontal-transmission shaft to an inclined-driving 
shaft. 

Q. How does it do this? 

A. The construction is such that the driving shaft is attached 
to one set of pins, while the driven shaft is attached to another, the 
axes of these intersecting in a common point. As the driven shaft can 
turn about its pins in one plane and, with the complete joint, about the 
driving shaft pins in another, as well as combinations of the two, 
complete freedom, or universal movement, is assured. 

Q. What are the power losses in a universal? 

A. In a well-designed and fitted universal joint, working prac¬ 
tically at zero angle, there is no loss, but as the angle increases, the loss 
increases until at about 20 degrees, it may reach 2 or 3 ner cent. 


700 


GASOLINE AUTOMOBILES 


Q. Why is such a joint needed? 

A. The final drive must be at the center of the rear axle, which 
is comparatively low, say 17 inches with 34-inch wheels or 18 inches 
with 36-inch wheels, while the power must originate at the engine 
which cannot be set as low as this, that is, the power must be gen¬ 
erated at a higher level than that at which it is used. An inclined 
shaft and universal joints must be used somewhere in the system. 

Q. What other considerations necessitate universal joints? 

A. The engine level varies little, while the rear end of the chassis 
varies up and down through a considerable range. In addition, the 
rear end carries perhaps 85 per cent of the load and sustains greater 
road shocks because of this fact. The design is such as to keep the 
front, or engine, end as quiet and as nearly stationary as is possible. 
These considerations necessitate a flexible connection between the two 
ends, so that one can move frequently and through considerable 
distances, while the other moves seldom and through very small 
distances. In addition, the rear end must sustain considerable side 
sway, so that freedom in a sidewise direction is necessary. The only 
way in which these necessities can be obtained is through the use of 
universal joints. 

Q. What is a slip joint? 

A. One which will allow sliding, or slipping, of one part or shaft 
within the other. Thus, under certain restraining conditions the rise 
and fall of the rear end may mean approaching or receding of that end 
to and from the front portion. With a slip joint, this is made easy. 

Q. What is the usual form of a slip joint? 

A. Generally, this takes the form of a squared shaft within a 
squared-out housing, although sometimes the square is rounded off 
to give a slight universal action. 

Q. What is the modern form of universal joint? 

A. A thin flexible disc of steel, leather, fiber, or laminated fabric, 
with the driving shafts bolted to two opposite points and the drive 
shaft bolted to two others between them has been found to be much 
simpler, lighter, cheaper, and better than the average universal, 
although it allows only limited angular motion. The engine is being 
gradually lowered, while the rear wheels are constantly being 
increased in size; so the difference of level is not as great as it was, and 
there is less need for the full universal. 


GASOLINE AUTOMOBILES 


701 


Q. What is the biggest advantage of these to the repair man? 

A. They allow the removal of a driving shaft, or a unit on either 
side of such a joint much more quickly and easily, with less work, 
than any other form, similarly, in replacement after the repair is 
completed. In addition, they have no loose parts to be lost or mis- - 
laid with consequent trouble and delay of the work. 

DRIVING SHAFTS 

Q. What is the usual type of driving shaft? 

A. The usual driving shaft is of small diameter and solid. 
Cold rolled steel is used on the lower priced cars, but forged steel 
machined at the ends (at least) is used on the better cars. On many 
of the most expensive machines, the shaft is fairly intricate in shape 
and is machined all over after forging, sometimes ground after har¬ 
dening. 

Q. What would be the advantage of a spring shaft? 

A. Being flexible, it would cushion the shocks so that none of 
these reached the engine. Such shocks as are induced by jerking 
the throttle wide open, or stepping on the accelerator pedal suddenly 
or, on the other hand, a sudden application of the brakes. 

Q. What is its real disadvantage? 

A. Being small, the owner of the car and the driver would 
always mistrust it, and would not feel free to drive as they would with 
a larger and more dependable shaft. 

Torque and Radius Rods 

Q. What is torque? 

A. Torque is turning effort, or force, ( applied to rotation, in the 
case of an automobile, to rotation of the driving shaft, and from it to 
the rear axle and wheels by means of the final reduction gears. 

Q. What is a torque rod? 

A. A rod, bar, or tube, provided to take, not the torque, but the 
equal opposite reaction from the torque application to the final drive. 

Q. What is the manifestation of this torque reaction? 

A. A tendency of the driving shaft and driving bevel gear to 
rotate up and around the bevel-driven gear in a counter-clockwise 
direction. 

Q. How does the torque rod absorb this? 

A. By extending this forward and attaching it to a frame cross- 


702 


GASOLINE AUTOMOBILES 


member at the front end and to the rear axle housing at the rear end, 
this counter-clockwise motion of the driving shaft is prevented. 

Q. What is driving effort? 

A. The force applied to the rear wheels tending to move the 
car forward. It is transmitted to the car, or frame of the car, as 
a push. 

Q. How is this push transmitted to the frame? 

A. In one of three ways; through special radius rods which 
transmit it directly to the frame; through a central tube which handles 
both torque and driving effort, transmitting this first to a frame cross¬ 
member, then to the main side members and through the springs, 
which are modified in attachment so as to take care of these extra 
stresses. 

Q. Which is the best form? 

A. The use of radius rods, one on each side, transmitting the 
stresses directly to the frame, is undoubtedly the best form, but also 
the most expensive, the heaviest, and includes the greatest number of 
parts. 

Q. Which is the most simple form? 

A. The use of the springs, the so-called Hotchkiss drive, but this 
also reduces the easy-riding qualities of the car because the springs, 
which should be flexible for easy riding, must be made somewhat 
rigid in order to transmit torque and driving reactions. 

Q. Which is the cheapest? 

A. Undoubtedly the use of the springs is the cheapest form, as 
it eliminates all additional parts, and simply necessitates a pivoted 
form of springing end in place of the usual shackle there. 

FINAL DRIVES 

Q. What are the usual methods of final drive? 

A. Final drive is usually by one of these methods: roller chain, 
silent chain, spur gear, bevel gear, spiral bevel gear, worm and gear, 
rollers. 

Q. Are all of these in use today? 

A. All but the roller, although the two forms of chain drive 
have almost gone out of use for pleasure cars and are becoming less 
popular even for truck use. 

Q. Which is most popular? ' 


GASOLINE AUTOMOBILES 


703 


A. For pleasure-car use, the spiral bevel form, and for motor 
trucks, the worm. 

Q. Why is the spiral bevel popular on pleasure cars? 

A. Because of its many advantages. It is just as simple as the 
straight bevel, needs no additional parts, is more quiet, perhaps more 
efficient, is less likely to cut or wear, can be removed as readily, and 
has other minor advantages. 

Q. Why is the worm popular for trucks? 

A. It has all the needed qualities; it is efficient, silent, easy to 
handle, and allows bigger gear reductions than any other form. 
Furthermore, various gear reductions are interchangeable by changing 
other parts, and the worm has other advantages. 

Q. Why is the worm not used more on pleasure cars? 

A. Because it is not so well adapted to high speeds of 50 to 60 
miles an hour and higher, which may be demanded, and because the 
large reduction between engine and rear axle, which is its biggest 
advantage, is not needed on pleasure cars. 

Q. What are the three mostly used forms of rear axle? 

A. The full floating, semi-floating, and three-quarter floating. 

Q. Which is the best form? 

A. From an engineering standpoint, the full floating is undoubt¬ 
edly the best, but it is also the most complicated, with the largest 
number of parts, and the most expensive to construct. 

Q. Which is the most simple form? 

A. The semi-floating form is the most simple, but it lacks 
advantages which the majority of car owners want. It is the cheapest 
to make, but is made so through the lack of these advantages. 

Q. Which is the compromise form? 

A. The three-quarter floating form seems to offer a maximum 
number of advantages with the minimum of disadvantages. It has 
practically all the advantages of the full floating with less cost. It 
has all the advantages which the semi-floating lacks and costs but 
little more. 

Q. Which is the most popular form? 

A. The floating still has the greatest number of makers, but the 
three-quarter form is rapidly gaining in popularity and, in another 
year, will displace the full floating as the most popular, both as to 
the number of makers and as to the actual number of cars. 


704 


GASOLINE AUTOMOBILES 


Q. Describe the internal=gear axle? 

A. In this form a spur gear is used to drive an internal gear of 
larger diameter. This construction enables the separation of load 
carrying and power transmitting, so that one part of the axle can 
handle each. 

Q. For what is this used mostly? 

A. The internal-gear axle is used mainly on motor trucks, 
although a few heavy pleasure cars have been built with it. 

Q. What is a differential? 

A. A mechanical device for allowing the rear wheels to travel 
different distances when turning a curve or corner. 

Q. How is this done? 

A. By combinations, or nests, of gears and a divided rear axle, 
one-half being fixed to each half of the differential, with only the nests 
of gears connecting the two. As these are free to revolve as a unit, 
or stand still and have their gears revolve, the drive can either be 
transmitted all to one wheel, half to each wheel, or divided unequally. 

Q. What is the usual differential form? 

A. The usual differential gear is constructed with bevel or 
spur gears, the bevel form being more popular, the spur cheaper. 

Q. What is undesirable in present differentials? 

A. Present differentials have the disadvantage that they work 
for resistance not distance. This permits the wheel, which we do not 
want to slip, to slip on icy places so that the car cannot pull itself free, 
the differential making a bad matter worse. 

Q. If the differential worked correctly, how could this be? 

A. In such a case, since the differential worked only for differ¬ 
ence in distance, and there was no difference in distance on an icy 
place, the power would be transmitted equally to the rear wheels. 
One would slip, but the other on firm ground would use its share of 
the power to pull the car off the icy place. 

Q. How is it expected that this result will be attained? 

A. By the use of helical gears, which, like the worm of a steering 
gear, are not reversible but will transmit powder only in one direction. 

Q. In addition to correct differentiation, what is it expected 
these differentials will do? 

A. Eliminate skidding, always dangerous and always a possi¬ 
bility with present forms. The connection between skidding and 


GASOLINE AUTOMOBILES 


705 


present differentials has never been explained, but can be readily 
proved by the simple process of building a car without a differential. 

Q. What forms of bearings are used in rear axles? 

A. All the different kinds of bearings are used in rear axles: 
plain ball, plain straight solid roller, straight flexible roller, tapered 
roller, a few plain bronze bearings, ball-thrust forms, and others. 

Q. Which form is most popular? 

A. There is little choice between the two forms of roller and the 
ball bearing. In fact, the majority of axles use several different forms 
of bearings; so it is difficult to compare the work of the various bearing 
types. 

Q. How can a broken spring clip be repaired? 

A. A good substitute for a spring clip can be made from two 
flat plates and four bolts to reach from one plate to the other. The 
purpose of the spring clip is to hold the spring to the axle; this combi¬ 
nation will do the same thing. 

Q. How would you line up a rear axle? 

A. With a try-square and plumb bob, working downward from 
the main frame, determine the distance from the rear end of the frame 
to the back side of the rear axle, on each side of the car. If the two 
do not agree exactly, the axle is out of square by the difference, or by 
half this difference on each side. Loosen the spring bolts, set the axle 
correctly, tighten the bolts, and check up the measurements again. 

BRAKES 

Q. What are the two general types of brakes? 

A. The contracting-band, which is an external brake, and the 
internal-expanding shoe. 

Q. How are these used? 

A. There is no set rule; some designers use only the internal¬ 
expanding form, claiming this is more powerful and dependable; 
others use only the band, claiming this is cheaper to make and repair 
and just as good; still others take no side but use both forms. 

Q. Has there ever been any agreement in relation to brakes? 

A. Up to about a year ago, it was general practice to use the 
internal-expanding shoe brake for the emergency, or hand, brake. 
This was the case whether the band form was used for the foot, or 
running brake, or another expanding shoe. 



700 


GASOLINE AUTOMOBILES 


Q. Does this rule hold now? 

A. No. Many hand-operated brakes are of the contracting- 
band form, while many foot-operated forms, which would be consid¬ 
ered the service, or running, brakes, are internal expanding. The 
tendency toward unit power plants is bringing back a shaft brake of 
the band type, operated by the hand lever. 

Q. Where are the brakes generally located? 

A. Except for the tendency just mentioned, the brakes have 
been located as much as possible in the rear wheels, on the assumption 
that this gave the most direct' and thus the best application of the 
braking force. 

Q. How are brakes arranged on the rear wheels? 

A. When both brakes are placed on the rear wheels, practice is 
sharply divided into two camps. The one places the running brakes 
as a band form on the outside of the drum, claiming this makes 
a smaller lighter drum, a more compact group on the wheel, and less 
expensive because the drum is cheaper. The other places the two 
brakes side by side, making both of the internal-expanding shoe form 
inside a wide drum, claiming this is more effective, more powerful, 
and that the brakes are better protected against dirt, dust, and water 
because entirely enclosed, and thus are more effective and need less 
attention. 

Q. What is the electric brake? 

A. A new device which substitutes the rotation of an electric 
motor for hand or foot application of the brakes. This is put into 
action by a finger lever on the steering post, which makes contact, 
through suitable resistance, between the battery and the motor. When 
the motor rotates a cable is wound up and this pulls the brakes. 

Q. Is this a powerful form? 

A. Not only very powerful but also very quick to act, so that 
care must be used in applying it. 

Q. What is the hydraulic brake? 

A. A new form for heavy trucks and tractors, in which the use 
of an oil, which transmits power equally and without loss, is substi¬ 
tuted for the usual rods and levers in the application of the brake. 
The construction is such that the driver can apply the brakes by a 
stroke of the hand lever, and if this does not give sufficient power to 
stop the truck, he can let the lever go forward and then pull it back- 


GASOLINE AUTOMOBILES 


707 


ward again; this action soes not release the brakes but does apply 
more force, that is, it can be worked continuously until sufficient 
power is applied to stop the vehicle, a peculiarity of this particular 
form. 

Q. What is the vacuum brake? 

A. A new form which utilizes the suction of the engine to create 
a vacuum in a special braking cylinder, the movement of a piston in 
which applies the brake. The amount of action depends on the 
amount of suction, that is, regulated by the amount the valve is 
opened, and this is dependent upon the pressure applied to the finger 
lever or toe button, whichever is used. 


WHEELS 

Q. Wha't are the usual forms of pleasure=car wheels? 

A. The plain wood form and the wire wheel comprise 99 per 
cent of all pleasure-car wheels; the wood forms about three-quarters 
and the wire about one-quarter of the total. 

Q. What are the tendencies in wheel sizes? 

A. On small cars the tendency is toward larger and larger sizes, 
but on the larger heavier cars the tendency is away from the very large 
sizes of a few years ago. The latter tendency has been brought about 
bv the standardization of tire sizes, and the elimination of 38s, 40s, 
and larger sizes formerly made. 

Q. What are the different forms of wire wheels? 

A. The double-spoke form, wdiich is lacking in lateral strength; 
the triple-spoke; and the quadruple-spoke. The Uvo latter make up 
in strength what the former double-spoke form lacked. Except for 
number of spokes, these do not look any different to the casual 
observer. 

Q. What is the sheet=steel wheel? 

A. A form in w T hich the whole wheel construction consists of a 
pair of sheet-steel members. These are given a slight taper, some¬ 
times have holes through them for ventilation and to make them 
lighter, and frequently are painted to resemble wood-spoke wheels. 
The steel sheets are made thin enough to be flexible. 

Q. What is the pressed=steel wheel? 

A. A new T er form in wffiich a simulation of one-half the entire 
wffieel spokes, hub and all, is pressed out of thin sheet steel, and a pair 


708 


GASOLINE AUTOMOBILES 


of these welded together so that the finished product has all the 
appearance of a wood wheel with the usual number of spokes, but 
without the rim which this construction eliminates. 

Q. What are the usual truck wheel forms? 

A. Most truck wheels are of heavy wood or cast steel. The 
latter do not weigh a great deal more than the former; because ol the 
greater strength of the material, less of it can be used. 

Q. Which is the most popular? 

A. The wood form is still the most popular, despite' its disad¬ 
vantages for heavy truck use, but the steel form is gaining rapidly?. 

Q. What are the advantages of steel? 

A. Greater strength, particularly to resist side stresses; better 
ventilation and removal of heat from the tires; more firm foundation 
for the tire so that it holds its shape better; and longer life at less cost. 

Tires 

Q. What are the general divisions of all tires? 

A. Pneumatic, cushion, and solid. 

Q. What is the principle of each? 

A. The pneumatic tire has an interior air bag which is pumped 
full of air, the tire gaining its resiliency from this. The cushion tire 
is so constructed as to have a central air passage or other yielding 
space so that it gives a cushion effect under loads. The solid tire is a 
solid mass of rubber, its only give being the natural yield of the rubber. 

Q. Is there a distinct field for each? 

A. Yes. Pneumatics are used only on pleasure cars and the 
lighter trucks or delivery wagons; cushion tires are used mostly on 
slow-speed electric pleasure cars and a few light trucks; solid tires are 
used only on the heavy trucks. 

Q. What is the big disadvantage of the pneumatic form? 

A. Its liability to puncture or blow out, or loose its air other¬ 
wise, after which the tire is useless until the fault is mended; in fact, 
the tires are actually in the way, and running a deflated tire only cuts 
it to pieces. 

Q. What are the divisions of pneumatic tires according to shape 
and method of holding? 

A. While there are other forms, practically all tires today are in 
one of two classes, the clincher or the straight side. 


GASOLINE AUTOMOBILES 


700 


Q. Describe the clincher type? 

A. This is made with a bead or hard portion at the base, which 
forms a projection around which the clincher rim fits. The rim has 
the shape of a flattened U with the ends curled in, and the beads on 
the tire fit into these curled ends or clinches. 

Q. What is the advantage of this? 

A. The clincher form is held firmly on the rim, while the stiffness 
of the bead contributes more rigidity of form and permanence of 
shape to the whole tire. 

Q. Describe the straight=side form. 

A. This type of tire has no bead, the fabric forming the side 
walls being carried straight down to form the base without additional 
thickness of material. 

Q. What are the advantages of this? 

A. Its simplicity and lighter weight, with greater air space are 
the advantages of the straight-side form. In addition, in the newly 
standardized rim forms, the form of rim adapted to the straight-side 
tire is more simple, lighter in weight, and lower in cost than any other. 
It has been found by experience that the holding power of the beads 
was unnecessary as the inflated tire could not come off the wheel 
whether it had a bead or not, since its diameter at the base could not 
be increased in any possible way sufficiently to pass over the larger 
size rim. 

Q. What is an oversize tire? 

A. In the standardization of tires and rims, for each even tire 
size, which is called a standard, there is an oversize made which will fit 
on the same rim without any other changes. 

Q. What is the difference between standard and oversize tires? 

A. All standard tires are made in even inches of outside diam¬ 
eter, and all oversize tires are made in odd inches of outside diameter, 
so that the rule for oversizes is this: An oversize is one inch larger in 
diameter and \ inch larger in cross-section, that is, the Ford size 
is 30 by 3J, the oversize for this, according to the rule, is 31 by 4; an 
average large car size is 36 by 4J, the oversize for this is 37 by 5. 

Rims 

Q. What are the general different rim forms? 

A. Rims are generally divided into these forms: plain, which is 


710 


GASOLINE AUTOMOBILES 


no longer used; clincher, which is gradually going out; quick-detach¬ 
able in its various forms; and demountable rims, now almost universal. 

Q. What are the differences in these? 

A. The clincher rim is a solid form, and the tire has to be 
stretched to get it on or off the rim. For this reason, it has to be made 
with a more or less yielding base, but even at that, tire removal is 
very difficult. The quick-detachable form is made with a locking 
ring on one side to replace the solid side of the clincher, so that tires 
can be applied easily. The demountable rim is a form which is used 
in combination with the others, this being a modification of the felloe 
of the wheel by which the entire tire and rim are removed in case of 
trouble, and then are replaced by another tire and rim which have 
been carried for this form. 

Q. What are the advantages of this? 

A. All roadside work is eliminated. When a puncture or 
blowout occurs, the driver simply jacks up his wheel, takes off tire 
and rim, and puts on the square tire and rim—the tire being inflated— 
lets down his car by means of the jack and drives off. The worn, or 
damaged tire, is carried at the rear in place of the spare, and is mended 
in the convenience and comfort of the garage or left at a tire repair 
station for that purpose. It saves work, time, and trouble at a time 
when these are of the greatest value to the owner. Given demount¬ 
able rims, supplied on the car by the manufacturer, the car can be 
operated with all these conveniences without extra tire expense. 

Q. How are demountable rims held in place on the wheels? 

A. Nearly all demountables are held by means of wedges, with 
separate bolts to press these into place, or else a construction in which 
the bolt and wedge are combined. 

TIRE REPAIRS 

Q. What is vulcanization? 

A. Vulcanization is the curing, or cooking, of raw rubber. By 
this curing it is more suitable for hard usage and its soft pliable 
character is changed without injuring its resiliency. If these wore 
unchanged the tire would cut and would not wear. 

Q. How is this accomplished? 

A. By the application of heat in moderate quantities and in dry 
form. The heat is not applied directly but through metal. In the 


GASOLINE AUTOMOBILES 


711 


usual tire-curing mold the central space for the tire is surrounded by 
metal, with a hollow annular space outside of this into which the 
steam, which is generally used, is introduced. The heat from this 
steam penetrates the metal inside and vulcanizes the tire. 

Q. Are all vulcanizers operated by steam? 

A. Practically all the larger ones are, but many of the smaller 
forms of the portable type burn gasoline in the heating space, others 
use electric resistance coils. 

Q. What is the advantage to the private owner of a vulcanizer? 

A. When a tire is cut badly, he can apply raw rubber as a patch 
or repair, and then vulcanize this for the double purpose of curing 
and of uniting it with the older part of the tire. In this way, tire life 
is much prolonged at little expense. 

Q. Is vulcanization profitable as a business for a repair shop? 

A. It is said to be highly profitable, after suitable equipment 
has been purchased and a trade built up. It is said to be a more 
steady and stable business than any other, for, as soon as an owner has 
been convinced of the value of vulcanization of tubes and casings, he 
will bring in all his tire repairs. 

Q. What is a sand blister? 

A. A small opening in a casing, into which sand has entered and 
continues to enter until the outer surface is swelled up just like a 
blister. If neglected, this will ruin the casing. 

Q. How should a sand blister be cared for? 

A. By the immediate removal of the sand and the cleaning of 
the cavity, after which it should be filled with a tire-repairing cement 
or tire-filling compound. The sand can be removed by cutting a small 
hole in the underside of the blister with a sharp penknife. 


i 







INDEX 


PAGE 


A 

Adjustable crankshaft flanges 83 

Air, pre-heating for carburetor 198 

Air cooling 300 

air jackets 301 

blowers, and fans - 301 

flanges, or fins 300 

internal cooling and scavenging 301 
Air cushion 554 

Air and gasoline supply 106 

auxiliary air valves 107 

double carburetors for multi¬ 
cylinder motors 111 

double-nozzle type 109 

multiple-nozzle carburetors 112 

nature of new development 110 

use of by-pass 110 

usual forms of auxiliary air-inlet 

valve 107 

Venturi-tube mixing chamber 108 
water-jacket ing 106 

Air-inlet valve, auxiliary 107 

Air jackets 301 

Aluminum, cleaning 88 

Annular bearings, adjusting 421 

Anti-freezing solutions 299 

Automatic gear-cutting machine 423 
Auxiliary air valve 107 

Axle bearings 501 

ball 502 

classification 501 

roller 502 

Axle pivots, inclining 446 

Axles, front 491 

B 

Ball and Ball carburetor 145 

Ball bearings 334, 502 

Bead of tire 674 

Bearing balls, saving 417 

Bearings 76, 330, 369 

ball bearings 334 

bearing wear 77 

clutch 369 

combined radial and thrust bear¬ 
ing « 337 

crankshaft pounding 78 

handy wrench 80 

holding for bearing caps 79 

plain bearings 331 

roller bearings *332 

test for tightness 78 

types of bearings required for 

different locations 330 


PAGE 


Becker gear-cutting machine 424 

Bennett air washer 185 

Bennett carburetor 181 

Bent rod, straightening 65 

Bevel gears 428, 454, 599 

Bevel pinion and sector steering 

gear 462 

Bevel type friction transmission 402 

Bilgram gear-planing machine 427 

Blowers 301 

Blowouts 693 

inside and outside method 695 

inside repair methods 694 

Brake adjustments 613 

Brake drums, truing 621 

Brake lining, stretching 620 

Brake lubrication 613 

Brake operation, methods of 610 

Brake troubles and repairs 617 

dragging brakes 617 

dummy brake drum useful 618 

eliminating noises 620 

to stop brake chattering 618 

stretching brake lining 620 

truing brake drums 621 

Brakes 604 

brake adjustments 613 

brake lubrication 613 

classification 605 

double-brake drum for safety 610 

electric brakes 613 

external-contracting brakes 605 

function of brake 604 

hydraulic brakes 614 

internal-expanding brakes 606 

methods of brake operation 610 

recent developments 613 

summary of instructions 699 

troubles and repairs 617 

vacuum brakes 615 

Brown and Sharpe gear-cutting 

machine 423 

Bushing removers 56 

By-pass, use of 110 

C 

Cable drives 402 

Cadillac carburetor 173 

Camber complicates axle ends 496 

Cams 232 

difficulties in making cams 244 

friction 232 

grinding increases accuracy 245 

number of valves per cylinder 239 



2 


INDEX 


PAGE 


Cams (continued) 

old way required more accurate 

inspection 245 

one cam for two valves influ¬ 
ences shape 242 

typical valve actions 236 

what good modern practice 

shows 238 

Camshaft 264, 271 

chain drive for 264 

twisted 271 

Cantilever spring 534 

Carbon deposits in cylinder 15, 31 

removal of 31 

carbon on fixed cylinder heads 31 
compressed air 33 

compression indicating gage 36 
liquid solvent 33 

removing carbon by scraping 

tools 33 

Carburetor 15, 99 

classification 101 

defects in original not found in 

modern types 101 

developments in 110 

effect of heavier fuels 99 

floats 105 

function of carburetor 99 

needle valves 104 

throttle valves 103 

Carburetor adjustment, general 193 
adjustments for heating water 

and air supply 194 

starving at high speeds 193 

tool for carburetor nozzles 193 

Carburetor and carburetion 99 

adjustment of air and gasoline 

supply 106 

fuel supply 210 

inlet manifold design and con¬ 
struction 201 

kerosene and heavy fuel carbu¬ 
retors 177 

summary of instructions 218 

troubles and remedies 190 

Carburetor on Ford cars 121 

Carburetor troubles and remedies 190 
Carter carburetor 164 

Casing repairs 692 

Cast axles 497 

Chain drive for camshafts 264 

Chain four-wheel drive 485 

Changing tires 650 

speed changes due to changed 

tires 652 

Chassis group 50S 

characteristics of parts 508 

frames 509 

shock absorbers 549 

springs 530 


PAGE 

Chassis group (continued) 
summary of instructions 563 

Circulation, water 293 

Cadillac system 296 

pumps 294 

thermosiphon 296 

Clincher rims 654 

Clutch forms in semi-, three- 
quarter, and full floating 
rear axles 584 

Clutch group 351 

details of clutch operation * 366 

summary of instructions 434 

types of clutches 351 

Clutch operation, details of 366 

clutch accessibility 370 

clutch adjustment 370 

clutch bearings 369 

clutch lubrication 368 

clutch pedals 367 

gradual clutch release 367 

methods 366 

Clutch troubles and remedies 370 

adjusting clutch pedals 378 

clutch spinning 375 

clutch troubles outside clutch 379 
cork inserts 375 

fierce clutch 374 

Ford clutch troubles 374 

handling clutch springs 373 

replacing clutch leathers 371 

slipping clutch 370 

summary 379 

Clutches, types of 351 

classification 351 

cone clutch 352 

contracting-band clutch 354 

expanding-band, or ring, clutch 355 
disc clutch 356 

magnetic clutch 364 

requirements applying to all 

clutches 351 

Coil-spring shock absorber 551 

combinations 552 

double-coil spring types 553 

springs alone 551 

Commercial-car wheels 636 

cast-steel wheels 639 

miscellaneous wheel types 639 

modern status of spring wheel 642 
requisites 636 

wood wheels 637 

Commercial-vehicle frame con¬ 
struction 523 

Compression, poor 16 

Cone clutch 352 

Connecting rod 61 

Connecting-rod bearings 63, 69 

adjustment of 69 

babbitting bearings 69 


INDEX 


3 


. PAGE 

Connecting-rod bearings (contin¬ 
ued) 

adjustment of 

drilling thin shims 72 

kinks in adjusting bearings 69 
mandrel for lapping 72 

special sleeve replaces shims 71 
Connecting-rod troubles and repairs 65 
adjustment of connecting-rod 

bearings 69 

classification of troubles 65 

straightening bent rod 65 

Construction of motor-car, general 

outline of 2 

Contracting-band clutch 354, 396 
Cooling, internal 301 

Cooling systems 286 

air cooling 300 

cooling troubles and adjustments 302 
water cooling 286 

Cooling troubles and adjustments 302 
adjusting fans 302 

adjusting pumps 303 

cleaning 302 

replacements 302 

washing 302 

Cord tires 653 

Couple-Gear wheel 490 

Crankcase 84 

Crankcase arms and engine supports 87 


Crankcase materials 
Crankcase oil 

Crankcase troubles and remedies 
cleaning aluminum 
general nature of troubles 
machining crankcase 
mending breaks 
Crankshaft 

Crankshaft and bearing troubles 
and remedies 
bearings 

crankshaft lapping 
handling shaft in machines 
holding crankshaft 
welding shafts and cases 
Crankshaft bearings 
Crankshaft and connecting-rod 
bearing shims 
Crankshaft lapping 
Cross-connecting rods 
Cut-outs 

Cycle in explosion motors 
four-stroke 
two-stroke 
Cylinder bore 
checking up 
grinding 

Cylinder and crankshaft sub-group 
connecting rods 
crankcases 


87 
329 

88 ' 

88 
88 
89 
88 
72 

76 

76 

83 
81 
81 

84 
75 

75 

83 
478 
286 

11 

11 

11 

40 

40 

41 
22 
61 

84 


PAGE 

Cyfinder and crankshaft sub-group 


(continued) 

crankshafts 72 

cylinder forms and construction 22 

pistons and accessories 48 

Cylinder forms and construction 22 

cylinders classified as to fuel 

chambers or valves 28 

materials used 22 

method of casting cylinders 24 

methods of classifying cylinder 

forms 23 

Cylinder heads 39 

Cylinder lapping, methods of 41 

Cylinder multiplication 12 

Cylinder oil, mixing with fuel 330 

Cylinder repairs 31 

checking up cylinder bore 40 

cylinder heads • 39 

grinding out cylinder bore 41 

locating noises by means of 

stethoscope 37 

making gaskets 38 

methods of cylinder lapping 41 

removal of carbon 31 

repairing cracked water jackets 43 

replacing pistons in cylinders 46 

simple dead center indicator 42 

welding breaks in cylinders 43 

working in valve cages 46 

Cylinders 28, 43 

classified 28 

I-head form 30 

L-head forms 28 

T-head forms 28 

welding 43 

D 

Dead center indicator 42 

Demountable rim tire types 647 

Demountable rims 660, 671 

comparison of continuous hold¬ 
ing ring type with local 
wedge type 667 

local wedge type 660 

process of changing Baker local 

wedge type 662 

rim with straight split 666 

for wire wheels 671 

Deppe gas generator 186 

Differentials on rear axles, effect of 589 

improved forms 591 

possible elimination 593 

Disc clutch 356 

floating discs 362 

greater power transmitted by 

surfaces not plane 362 

metal-to-metal dry-disc type 359 

multiple-disc clutches 358- 

popularity 356 


4 


INDEX 


PAGE 

Disc clutch (continued) 

Engine troubles (continued) 

PAGE 

simple types 

357 

popping in carburetor 

15 

two forms of same make 

356 

Ensign fuel converter 

189 

use of facings 

360 

Ensign heavy fuel carburetors 

188 

Disc individual clutch 

396 

Epicyclic, or planetary, gears 

399 

Double-brake drum for safety 

610 

Exhaust gases, importance 

of 

Double carburetors for multicylin¬ 


handling properly 

279 

der motors 

111 

Exhaust manifolds, forms of 

280 

Double-chain drive 

576 

Exhaust system 

279 

Double-nozzle carburetor 

109 

cut-outs 

286 

Drag link 

474 

forms of exhaust manifolds 

280 

Driving reaction 

579 

importance of handling exhaust 

Drop forgings for front axles 

498 

gases properly 

279 

Dropped rear axle of full floating 


muffler 

284 

type 

583 

Exhaust-valve setting 

249 

Dummy brake drum useful 

618 

Expanding-band clutch 

355 

Dunlop tire 

645 

Exterior lubrication 

305, 318 

demountable rim types 

647 

External-contracting brakes 

605 

non-skid treads 

647 

F 


E 


Failure to start engine 

15 

Electric brakes 

613 

Fans 298, 

301, 302 

Electric car springs 

541 

Fellows gear shaper 

424 

Electric drive 404, 405, 

489 

Fergus frame 

516 

Couple-Gear type 

490 

Filler cap 

201 

Electric generating clutch 

364 

Final-drive group 

8, 569 

Electric transmissions 404, 

405 

brakes 

604 

Electrically operated gears 

393 

driving shaft 

8 

Elliott front axle 

492 

rear axle 

569 

reversed Elliott 

492 

rear axle and differential 

9 

Engine 15 

, 57 

summary of instructions 

699 

failure to start 

15 

tires 

645 

speeding up old 

57 

wheels 

625 

Engine group 

3 

Fins 

300 

carburetion sub-group 

3 

Flanges 

300 

cooling system 

5 

Flat-plate recoil springs 

554 

cylinder and crankshaft sub-group 3 

Flexible joints 

572 

exhaust system 

5 

Floating disc clutch 

362 

flywheel 

.*-7 

l 

Floats 

105 

ignition system 

5 

Flywheel characteristics 

337 

inlet and exhaust valves 

5 

Flywheel markings 

246 

lighting system 

7 

Flywheel sub-group 

337 

lubrication system 

6 

characteristics 

337 

starting system 

6 

importance 

337 

Engine-group elements 

11 

markings 

339 

Engine repairs 

16 

methods of fastening 

339 

Engine troubles 

15 

Folding steering wheels 

473 

deposits of carbon in cylinder 

15 

Ford axles, checking up 

603 

engine pulls on high speed but 


Ford cars, carburetors on 

121 

not on low speed 

16 

Ford clutch troubles 

374 

engine runs well on low speed 


Ford planetary gears 

400 

but not on high speed 

16 

Ford spring 

540 

engine starts but stops after few 


Ford steering gear 

465 

revolutions 

16 

Forgings for front axles 
Four-cycle motor 

498 

failure to start 

15 

- 11 

knocking 

15 

Four-stroke cycle 

11 

knocking continues even after 


Four-wheel driving, steering, , 

and 

spark is properly adjusted 

16 

braking 

482 

missing of explosions 

15 

advantages of four-wheel drive 489 

poor compression 

16 

chain four-wheel drive 

485 


INDEX 


5 


PAGE 

Four-wheel driving, steering, and 
braking (continued) 

Jeffery Quad 485 

Frame bracing methods 529 

Frame group 10 

Frame troubles and repairs 525 

fracture 526 

frame bracing methods 529 

riveting frames 527 

sagging - 525 

Frames 508 

classes of frames 510 

effect on springs 513 

general characteristics 509 

pressed-steel frames 512 

rigid frame 513 

sub-frames 513 

summary of instructions 563 

tendency in design , 511 

troubles and repairs 525 

types 515 

Friction disc 401 

bevel type 402 

spur type 401 

Frictional-plate shock absorber 550 
Front-axle troubles and repairs 503 
alignment of front wheels 

troublesome 503 

spindle troubles and repairs 507 

straightening axle 505 

wobbling wheels 507 

Front axles 491 

axle bearings 501 

materials 497 

troubles and repairs 503 

types 491 

Front-wheel drive 480 

control 482 

difficulties of transmission 480 

friction-disc transmission 481 

Fuel 99 

effect of heavier 99 

explosibility 8 

Fuel feeding 210 

Fuel line 217 

lock on 218 

obstructed 217 

Fuel spray, methods of handling 106 
Fuel supply 2 JO 

fuel feeding 210 

piping and connections 215 

reserve tanks . 216 

tank placing 210 

Fuel system troubles and repairs 217 
Full-elliptic spring 532 

Full floating axle 581, 086 


G 


Gaskets, making 
Gasoline 


38 

201 


PAGE 

Gasoline automobiles 1-349, 351-711 
bearings 330 

carburetors and carburetion 99 

chassis group 508 

clutch group 351 

cooling systems 286 

cylinder and crankshaft sub¬ 
group 22 

engine-group elements 11 

final-drive group 569 

flywheel sub-group 337 

general outline of construction 2 

introductory 1 

lubrication system 305 

steering group 445 

summary of instructions 91, 340 

transmission group 380 

valves and their mechanism 227 

Gasoline line 201 , 217 

Gasoline railway cars, transmis¬ 
sion needs of 395 

Gasoline strainer 191 

Gasoline tank, filling 191 

Gear cases 87 

Gear control 271 

Gear-cutting machines, types of 421 
automatic 423 

Becker 424 

Bilgram 427 

Brown and Sharpe 423 

Fellows 424 

Gleason 425 

Whiton 422 

Gear operation, noise in 409 

Gear pitch and faces 433 

Gear pullers 411 

Gear shifting 

pneumatic system 395 

poor 412 

Gear troubles 433 

Gears 421 

types of gear-cutting machines 421 
types of gears in automobile 428 
Gears in automobiles 428 

bevel 428 

gear pitch and faces 433 

gear troubles 433 

helical and herringbone 429 

spiral * 430 

spiral bevels 431 

worm gears 432 

Gleason gear planer 425 

Gravity feeding 317 

Gravity-return layout of tire re¬ 
pair equipment 685 

Grease cups 330 

Grease gun, mammoth 325 

Greases 322 


6 


INDEX 


PAGE 


PAGE 

H 


Jeffery Quad 


485 



Johnson carburetor 


161 

H. & N. carburetor 

167 




Haywood vulcanizer 

679 

K 



Heating charge 

205 




Heavier fuel, effect of 

99 

Kerosene carburetors 


177 

Heavy fuel carburetors 

177 

Kingston carburetor 

121, 

130 

Helical gears 

429 

Knight motor, timing 


276 

Herringbone gears 

429 

Knight sleeve valves 


272 

Hindley worm gear 

464 

Knocking in engine 


15 

Hoists and cranes 

18 

Knox “F” carburetor 


169 

commercial forms 

20 

Knox tractor spring 


538 

floor type of hoist support 

19 




form of cradle 

20 

L 



home-made ceiling hoist 

18 




portable engine stands 

21 

L-head cylinder forms 


28 

Yale & Towne form 

18 

Leinoine front axle 


494 

Holley all-fuel carburetor 128, 

178 

inverted Lemoine 


495 

Holley carburetors 121, 

177 

Locomobile, spring 


541 

Holley kerosene carburetor 

177 

Lubrication 60, 305, 368, 

398, 


Hotchkiss drive 

536 

420, 480, 546, 

594, 613 

Hydraulic brakes 

614 

curing excessive 


60 

Hydraulic clutches 

364 

exterior 

305, 318 

Hydraulic gear 

403 

general 


321 

Janney-Williams 

403 

gravity feeding 


317 

Manly 

403 

individual pump pressure feeding 317 

Hydraulic suspensions 

557 

interior 


305 


J 

neglect of 


330 

I 


principles of effective 


323 

I-head cylinder forms 

30 

single-pump pressure feeding 

308 

Individual clutch 

395 

splash lubrication 


318 

general types used 

395 

splash-pressure feeding 


306 

transmission adjustments 

399 

troubles and remedies 


325 

transmission bearings 

399 

bending oil pipes 


329 

transmission lubrication 

398 

care of lubricant in 

cold 


transmission operation • 

398 

weather 


325 

Individual pump pressure feeding 

317 

mammoth grease gun 


325 

Inlet manifold design and con¬ 


oil filtering outfit 


328 

struction 

201 

oil settling tanks 


328 

changes 201, 

206 

oil tank and outfit for testing 


heating charge 

205 

bearings 


326 

hot spots in manifolds 

206 




inlet manifold troubles 

209 

M 



Inlet valve, troubles with 

262 




Inner tube repairs 

689 

Magnetic clutch 


364 

Inner tubes, improvement in 

653 

Mandrel for turning pins 


57 

Interlocking devices for gears 

391 

Manifold, changes in 

201, 206 

Internal dogs, individual clutch 


for eights and twelves 


204 

using 

395 

from fours to sixes 


203 

Internal-expanding brakes 

606 

Manly hydraulic gear 


403 

Internal-external gear individual 


Marmon self-lubricating axle 


495 

clutch 

397 

Marmop spring 


537 

Internal-gear drive for trucks 

585 

Marvel carburetor 


152 

Internal cooling and scavenging 

301 

Master carburetor 

133, 181 

Interior lubrication 

305 

Metal-to-metal dry-disc clutch 

359 



Miller racing carburetor 


135 

J 


Misfiring, causes of 


199 

Jacking-up troubles 

594 

Missing of explosions 


15 

substitute for jack 

595 

Motor-car construction 


2 

Janney-Williams hydraulic gear 

403 

clutch group 


7 


INDEX 


7 


PAGE 

Motor-car construction (continued) 


engine group 1 '> 3 

final-drive group 8 

frame group 10 

groups and parts 2 

steering group 9 

transmission group 7 

Motor lubrication 305 

Muffler 284 

troubles - 286 

Multiple-disc clutches 358, 379 

Multiple-nozzle carburetors 112 

N 

Needle valve 104, 201 

Needle valve stem, bent 191 

Newcomb air-heated carburetor 151 
Newcomb carburetor 148 

Noisy bevel gears 599 

Noisy tappet 390 

Noisy valves 260 

Non-leaking rings 59 

Non-return layout of tire repair 

equipment 685 

Non-skid treads 647 

Nozzle, adjustment of 194 

O 

Oil barrels 326 

Oil filtering outfit 328 

Oil pipes, bending 329 

Oil settling tanks 328 

Oil tank and outfit for testing 

bearings 326 

Oilless bearings 332 

Oils and greases 322 

characteristics of good oils 322 

principles of effective lubrication 323 
testing oils for acid, etc. 323 

Outer shoe repairs 692 

blowouts 693 

classifying troubles 692 

retreading 696 

rim-cut repair 695 

sand blisters 693 

summary 698 

use of reliner 698 

Oversize tires, use of 649 

Oxygen-adding devices 176 

P 

Packard bevel adjustment 599 

Packard carburetor 172 

Parker pressed-steel wheels 635 

Parker rim-locking device 672 

Parrett air cleaner 186 

Patches on inner tubes 689 


PAGE 


Pedals, clutch 367, 378 

Perlman rim patents 668 

Piping and connections for fuel 

supply 215 

Piston and accessories 48 

characteristics of piston rings 49 

piston construction 48 

piston pins 52 

types of piston rings 51 

Piston pins 52 

Piston and ring troubles and re¬ 
pairs 46, 53 

bushing removers 56 

curing excessive lubrication 60 

freeing wrist pins and bushings 55 
loosening seized pistons 55 

mandrel for turning pins 57 

mounting pistons on lathes 61 

non-leaking rings 59 

removal and replacement of 

pistons 46, 53 

testing size of new piston 59 

tracing ring knock 60 

Piston rings 49 

Plain bearings ' 331 

Plain rim 654 

Planetary gears 399 

Ford type 400 

method of action 399 

Platform spring 533 

Pleasure-car steering wheels 471 

Pleasure-car wheels 624 

Parker pressed-steel wheels 635 

sheet-steel wheels 632 

wire wheels 628 

wood wheels 624 

Pneumatic drive 404 

Pneumatic system of gear shifting 395 
Pneumatic tires 645 

Poppet-valve gears 232 

cams 232 

repairing poppet valves and 

valve parts 252 

valve timing 246 

Poppet valves and valve parts, re¬ 
pairing 252 

adjusting tension of valves 257 

chain drive for camshafts 264 . 

cleaning camshaft gears 270 

curing noisy tappet ^ 252 * 

cutting valve-key slots 258 

grinding valves 258 

holding valve springs compressed 256 
noisy valves 260 

parts of valve system . 265 

push rods and guides 266 

removing valve 252, 261 

removing valve spring 253 

troubles with inlet valves 262 

twisted camshafts 271 





8 


INDEX 


PAGE 

Poppet valves and valve parts, re¬ 


pairing (continued) 
valve cage repairs 267 

valve caps 269 

valve enclosures 261 

valve guides 268 

valve timing gears 262 

Popping in carburetor 15 

Pressure feeding, individual pump 317 
Progressive gears 381 

Pumps, adjusting 303 

Punctures in tires, repairing 689 

Push rods and guides 266 

Q 

Q.D. rim 654 

Quick-detachable rim 654 

clincher forms 659 

No. 2 657 

type for straight sides 660 

R 

Radial and thrust bearings 337 

Radiators and piping 289 

modifications of cellular and 

tubular forms 292 

types of cells 291 

types of tubes 291 

Rayfield carburetor 141 

Rear axle carrying load and drive 582 
Rear-axle housings 589 

Rear-axle lubrication 594 

Rear-axle troubles and repairs 594 
checking up Ford axles 603 

jacking-up troubles 594 

locating trouble 602 

noisy bevel gears 599 

rear axle 597 

universal-joint housings 596 

workstand equipment 595 

Rear axles 569 

summary of instructions 699 

transmission 569 

troubles and repairs 594 

types of rear axles 581 

Rear construction, disassembling 

and assembling 598 

Rear-end of frame, changes in 523 

Rear-wheel bearings 593 

Reliner, use of 698 

Repairs 16, 31, 43, 53, 65, 76, 

88, 190, 217, 252, 302, 325 
Replacements 302 

Reserve tanks 216 

Retreading 696 

building up tread 697 

repairing carcass 696 

Retreading vulcanizers 684 

Reversed Elliott front axle 492 


PAGE 


Rigid frame 513 

Rim-cut repair 695 

complete rim cut 696 

partial cut 695 

Ring clutch 355 

Ring knock, tracing 60 

Roller bearings 332, 502 

Rotating valves 278 

S 

Sand blisters 693 

Scavenging 301 

Schebler carburetors 155 

Selective types of sliding gears 381, 382 
four-speed type with direct 

drive on high 383 

four-speed type with direct drive 

on third 385 

Semi-elliptic spring 531 

Semi-elliptic truck spring 538 

Semi-floating rear axle 581, 584 

Semi-reversible gear 467 

Seven-eighths floating rear axle 581 
Shackles for springs 54 4 

Shaft drive 573 

Shakespeare carburetor 171 

Shaler vulcanizer 679 

Shock absorbers 509, 549 

air cushion 554 

coil springs 551 

flat-plate recoil springs 554 

frictional-plate 550 

function 549 

general classes of absorbers 549 

hydraulic suspensions 557 

overload springs 558 

summary of instructions 566 

Side-wall vulcanizer 683 

Silent-chain drive 577 

Single-disc individual clutch 396 

Single-pump pressure feeding 308 

Marmon 312 

methods of driving pumps 313 

types of oil pumps 312 

Sliding gears 381 

electrically operated gears 393 

general method of operation 381 
interlocking devices 391 

<4nodern selective types 382 

pneumatic shifting system 395 

progressive type 381 

railway car needs 395 

selective type 381 

transmission location 385 

Sliding-sleeve valves 271 

gear control 271 

Knight sleeve valves 272 

timing Knight motor 276 

Slip joints 571 

Small tool tire repair equipment 687 


INDEX 


9 


PAGE 


Spark lever 474 

Spindle troubles and repairs 507 

Spiral bevel gear 431 

Spiral gears 430 

Splash lubrication 327 

Spring clips, repair for broken 600 

Spring troubles and remedies 546 

broken springs 548 

general hints on spring repairs 548 
lubrication 546 

tempering or resetting springs 548 
Spring wheels 639 

Springs 373, 509-, 530 

adjusting spring hangers 544 

basis of classification 530 

cantilever 534 

clutch 373 

full-elliptic 532 

Hotchkiss drive 536 

platform 533 

semi-elliptic 531 

shackles and spring horns 544 

spring construction and materials 546 
spring lubrication 545 

summary of instructions 566 

three-quarter elliptic 532 

troubles and remedies 546 

unconventional types 537 

varying methods of attaching 

springs 542 

Spur gears 428, 454 

Spur type friction transmission 401 

Steering-gear assembly troubles 

and repairs 469 

lost motion and backlash 469 

lost motion in wheel 469 

Steering gears 330, 445 

action of wheels in turning 447 

Ford steering gear 465 

general characteristics of steer¬ 
ing gears 450 

general requirements 445 

inclining axle pivots 446 

removing 468 

semi-reversible 467 

spur and level 454 

steering levers in front of axle 448 
troubles and remedies 469 

worm-gear 455 

Steering group , 9, 445 

front axles 491 

gears 445 

rod, or drag link 474 

special types of drive 480 

summary of instructions 558 

wheels 470 

Steering knuckles 479 

Steering levers in front of axle 448 

Steering rod 474 


PAGE 


Steering rod (continued) 

cross-connecting, or tie, rods 478 

function and shape of steering 

knuckles 479 

lubrication of steering-gear as- 

semblv 480 

operation 474 

types of construction 476 

Steering wheels 470 

different forms of hand wheels 470 

different wheels for commercial 

use 471 

throttle and spark, levers 474 

Stewart carburetor 158 

Stromberg carburetors 112 

Stromberg Ford carburetor 125 

Sub-frames 513 

Summary of instructions 91, 218, 340 
Sunderman “Nitro” carburetor 170 

T 

T-head cylinder forms 28 

Tables 

Royal Automobile Club’s com¬ 
mittee report on Knight 
engine 274 

timing regulation of American 

motors 234 

timing regulation of French 

motors 233 

Tank placing 210 

Tappet, noisy 252 

Testing oils for acid, etc. 323 

Testing size of new piston 59 

Three-quarter elliptic spring 532 

Three-quarter floating axle 

581, 584, 588 
Throttle lever 474 

Throttle loose on shaft 192 

Throttle valves 103 

Thrust and radial bearing 337 

Tie rods 478 

Tillotson carburetor 168 

Tire construction 673 

bead 674 

composition and manufacture 673 
tire valves 675 

Tire improvements, recent 652 

cord tires J 653 

inner tubes 653 

tire valves 652 

Tire inflation pressures, proper 648 
use of standard pressure and 

oversize tires 649 

Tire repair, materials used 689 

Tire repair-equipment 677 

inside casing forms 683 

layouts of equipment 685 

materials 689 


10 


INDEX 


PAGE 


Tire repair equipment (continued) 
retreading vulcanizers 
separate casing molds for patch 
work 

side-wall vulcanizer 
small tool equipment 
types of vulcanizing outfits 
vulcanization of tires for repair 
man 

vulcanizing kettles 
Tire repairs 

inner tube repairs 
outer shoe, or casing, repairs 
repair equipment 
Tire rims 
clincher 
demountable 
kinds 

Perlman rim patents 
other removable forms 
plain 

quick-detachable 
standard sizes 
Tire valves 
action 

improvement in 
leaky valves 
Tires 
kinds 

pneumatic tires 
rims 

summary of instructions 
tire construction 
tire repairs 

Tires and rims, standard sizes 
Toquet Ford atomizer 
Torque bar 
Transmission 
driving reaction 
other flexible joints 
slip joints 

torque bar and its function 
types 

units in final drive 
universal joints 
Transmission adjustments 
Transmission bearings 
Transmission group 
classification 
freak drives 
friction disc 


6S4 

681 

683 

687 

679 


gears 


individual clutch 
miscellaneous types 
planetary gears 
sliding gears 
summary of instructions 
troubles and repairs 
Transmission location 

amidships alone or with clutch 


677 
682 
677 
689 
692 
677 
654 
654 
666 
654 
668 
671 
654 
654 
669 
652, 675 
676 
652 

676 
645 
645 
645 
654 
699 
673 

677 
669 
125 
577 
569 
579 
572 

571 
577 

572 

569 

570 
399 
399 

7, 380 

380 
402 

401 
421 
395 

402 
399 

381 
439 
409 
385 
387 


PAGE 

Transmission location (continued) 
amidships joined with driving 

shaft 387 

rear unit with rear axle 389 

unit with engine 385 

Transmission lubrication 398, 420 
Transmission operation 398 

Transmission troubles and repairs 409 
care in diagnosis 412 

cleaning transmission gears 414 

gear pullers 411 

handy spring-tool 417 

heating 410 

lifting out transmissions 415 

noise in gear operation 409 

poor gear shifting 412 

possible troubles 418 

pressing gears on shafts 411 

saving balls 417 

summary 420 

transmission stands 415 

working in bearings 416 

Troubles 15, 53, 65, 76, 88, 

190, 209, 217, 302, 325 
Truck types of steering wheels 471 
Truss rods 597 

Tubular axles 499 

drop-forged ends 499 


U 


Underpans, steel 521 

Underslinging springs 543 

Universal-joint housings 596 

Universal joints 570 

V 

Vacuum brakes 615 

Valve 227, 236, 252, 257 

action of 236 

adjusting tension 257 

grinding 258 

importance of 227 

noisy 260 

number per cylinder 239 

removing 252 

summary 227 

taking out 261 

Valve cage 46, 267 

Valve caps 269 

Valve enclosures 261 

Valve guides 268 

Valve-key slots, cutting 258 

Valve mechanism 227 

exhaust system 279 

poppet-valve gears 232 

rotating valves 278 

sliding-sleeve valves 271 

Valve spring 253 

holding compressed 256 


INDEX 


11 


PAGE 

Valve spring (continued) 

removing 253 

stretching and tempering 256 

Valve-stem clearance 248 

Valve system parts 265 

Valve timing 246 

exhaust-valve setting 249 

relation of settings in each 

cylinder 249 

system applies to all types of 

motors 250 

valve-stem clearance 248 

Valve timing gears 262 

Venturi-tube mixing chamber 108 

Vulcamzation of tires 677 

Vulcanizers, retreading 684 

Vulcanizing kettles 682 

Vulcanizing outfits 679 

Haywood 679 

inside casing forms 683 

retreading vulcanizers 684 

separate casing molds for patch 

work 681 

Shaler 679 

side-wall vulcanizer 683 

vulcanizing kettles 682 

W 

Water cooling 286 

anti-freezing solutions 299 

circulation 293 

fans 298 

radiators and piping 289 


PAGE 

Water-jacketing 106, 287 

built-on jackets 288 

internal jackets 287 

welded applied jackets 288 

Water jackets, repairing cracked 43 
Webber automatic carburetor 137 

Welding 43, 84 

Wheel pullers 643 

Wheel sizes 622 

advantages of large wheels 622 

Wheel troubles and repairs 643 

W’heels 447, 622 

action in turning 447 

commercial-car wheels 636 

pleasure-car wheels 624 

summary of instructions 699 

troubles and repairs 643 

wheel sizes 622 

Whiton gear-cutting machine 422 

Winton spring 539 

Workstand equipment 595 

Worm gears 432, 455 

Worm type steering gear 455 

Hindley worm gear 464 

worm and full gear 456 

worm and nut 458 

worm and partial gear 455 

worm and worm 461 


Wrist pins and bushings, freeing 55 

Z 

116 


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